Input device for a computer and the like and input processing method

ABSTRACT

The input device which includes a reflection type optical sensor having light emitting means and light receiving means; an operation section disposed facing the optical sensor, the operation section being tilted when a load is applied thereto; and output means for detecting a tilt status of the operation section based on signals from the light receiving means and outputting detected results to a computer body as positional information.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an input device for shifting theposition of a cursor or an icon on a display screen for a computer orthe like, and an input processing method using such an input device.

2. Description of the Related Art

Conventionally, a track ball and mouse have been used as a pointingdevice, i.e., an input device for shifting the position of a cursor oran icon on a display screen. As shown in FIG. 91, a track ball 1 islocated, for example, on a keyboard 3 of a personal computer 2. A ball 4portion of the track ball 1 is rotated with a finger, so as to allow acursor or an icon on a screen of the personal computer 2 to shift in adirection and by an amount determined by the direction and amount of therotation of the ball 4.

Referring to FIG. 92, the operational principle of the track ball 1 willbe briefly described. Rotary encoders 7 and 8 are disposed in twodirections, X axis and Y axis, with respect to the ball 4. The encoders7 and 8 include rollers 5 and 6, respectively, for detecting thedirection and amount of rotation of the ball 4. The rotary encoders 7and 8 generate signals indicating the direction and amount of therotation of the ball 4. The signals are converted into electric signalscorresponding to the X-axis direction and the Y-axis direction, and aretransmitted to the circuitry included as part of the personal computerbody. The computer body instructs the cursor or the icon on the screento shift according to the received signals.

Each of the rotary encoders 7 and 8 includes a rotary plate 11 having aplurality of slits 10 and two sets made up of an LED 12 and a lightreceiving element 13 disposed to face each other with the rotary plate11 therebetween. The rotary encoders 7 and 8 are connected to shafts 9aand 9b in the X-axis and Y-axis directions, respectively. When the ball4 rotates in the X-axis direction, for example, the shaft 9a in theX-axis direction rotates, which rotates the rotary plate 11 of therotary encoder 7. The rotation of the rotary plate 11 allows lightemitted from the LEDs 12 to be pulsed as a result of passing through theslits 10. The pulsed signal is then converted into an electric signal bythe light receiving elements 13. Thus, the rotational direction and thenumber of increments of rotation of the rotary plate 11 are detected,and thereby the amount of rotation of the ball 4 in the X-axis directionis determined. The position of the cursor or the icon on the screen isthus shifted in a direction on the screen corresponding to the X-axisdirection by the determined amount of rotation. When the rotationaldirection of the ball 4 is 45° with respect to the X axis and the Yaxis, signals indicating the rotational direction and the same amount ofrotation are obtained from both the X-axis and Y-axis rotary encoders 7and 8 simultaneously. In such a case, the position of the cursor or theicon shifts obliquely according to the signals from the X-axis andY-axis rotary encoders 7 and 8 as is known.

Now, referring to FIGS. 93 and 94, a mouse will be described. A mouse 15has a ball 16, similar to the ball 4 of the track ball 1, in the lowerposition thereof. The mouse 15 is moved forward, backward, rightward,and leftward on an operation board 17 or on a desk, so as to shift acursor or an icon on a computer screen. Then, a click button 18 ispressed to conduct an input operation. The inner structure of the mouse15 is substantially the same as that of the track ball 1.

In the track ball 1, the rollers 5 and 6 which transmit the rotation ofthe ball 4 to the rotary encoders 7 and 8 may slip on the ball 4. Thismay cause malfunction of the track ball 1. Further, since it isstructurally difficult to seal the rotary encoders 7 and 8, the slits 10may be clogged with dust which has entered inside of the rotary encoders7 and 8. This may also cause malfunction of the track ball 1. Moreover,since spaces for the track ball 1 and a mechanical operation portion forthe track ball 1 are required, it is difficult to reduce the size of thepersonal computer.

The mouse 15 has the same problem as the track ball 1 since themechanism for detecting the rotation of the ball 16 is the same as thatof the track ball 1. Additionally, since the mouse 15 is separated fromthe personal computer and moved on the operation board 17 or on a deskso as to rotate the ball 16, a plane for moving the mouse 15 isrequired. Accordingly, the mouse is not applicable to small-sizeportable personal computers.

Instead of the above-described mechanical mouse 15, there is alsoavailable an optical mouse where a light emitting element and a lightreceiving element are provided to detect an amount of movement of themouse in each of the X-axis and Y-axis directions. The optical mouserequires no mechanical operation portion. However, it requires aspecific operation board on which the mouse is maneuvered. Therefore,the problem of the mouse requiring an additional operation space is notsettled.

FIGS. 95A, 95B, and 96 show a pointing stick 20 which requires a smalleroperation space than the track ball 1 and the mouse 15. The pointingstick 20 includes a rectangular parallelopiped resin rigid body 21,distortion sensors 22 attached to the four faces of the rigid body 21,and a cylindrical cover 23 covering the rigid body 21 with a spacetherebetween. When the cover 23 is pressed, the distortion sensors 22detect the direction of the pressing. A cursor or an icon is shiftedaccording to the detected direction. The pointing stick 20 with theabove structure is disposed between keys 26 in a keyboard 25 of apersonal computer body 24 as shown in FIG. 96. This arrangement makes itpossible to significantly reduce the area and volume occupied by thepointing stick 20. However, since the pointing stick 20 is of a contacttype using a contact or a distortion sensor, the reliability and thedurability are low. Accordingly, a non-contact type with highreliability and durability is desirable for a frequently-used pointingdevice. The pointing stick 20 is also disadvantageous in the aspect ofcost because the configuration for subsequent input processing iscomplicate.

The above conventional input devices only allow the cursor and the liketo shift upward, downward, rightward, and leftward. With the recentadvent of the computer graphics, it becomes necessary to also shift thecursor and the like in the depth direction of the screen. In theconventional input devices, three-dimensional screen control is notpossible.

Two-dimensional input operation is possible for all of the above inputdevices (pointing devices). However, there requires separate switchesfor a click function and a drag function to realize the input operation.These switches prevent the input devices from being made smaller andmore compact.

SUMMARY OF THE INVENTION

The input device for a computer of this invention includes: a reflectiontype optical sensor having light emitting means and light receivingmeans; an operation section disposed facing the optical sensor, theoperation section being tilted when a load is applied thereto; andoutput means for detecting a tilt status of the operation section basedon signals from the light receiving means and outputting detectedresults to a computer body as positional information.

Alternatively, the input device for a computer of the present inventionincludes: light emitting means for emitting a light; two positionsensitive detectors for optically detecting a position on which thelight is incident and outputting signals in accordance with a detectionresult; and output means for outputting to a computer body screen inputinformation based on the signals from the two position sensitivedetectors.

Alternatively, the input device for a computer of the present inventionincludes: a movable body which displaces upon receipt of a load in atwo-dimensional direction; a light emitting element for emitting light;and a light receiving element for receiving an image of the light fromthe light emitting element shifting in association with the displacementof the movable body, wherein the movable body, the light emittingelement, and the light receiving element are integrally formed.

According to another aspect of the invention, an input device for acomputer having a three-dimensional input function for a display of thecomputer is provided. The device includes: a movable body whichdisplaces three-dimensionally upon receipt of a load in athree-dimensional direction; a light emitting element for emittinglight; a light receiving element optically coupled with the lightemitting element for receiving an image of the light shifting inassociation with the displacement of the movable body; and an opticalsection for regulating the light passing toward the light receivingelement, wherein the light emitting element, the light receivingelement, and the optical section are integrally formed.

According to still another aspect of the invention, an input processingmethod for an input device for a computer is provided. The methodincludes the steps of: detecting a shift of an image of light emittedfrom a light emitting element and shifting in association with adisplacement of a movable body; determining from the shift of the imageof light vectors in two directions crossing each other at right anglescorresponding to a direction and amount of the displacement; andsynthesizing the vectors in the two directions to obtain a synthesizedvector and calculating a direction and amount of operation from thesynthesized vector.

Alternatively, the input processing method for an input device for acomputer of the present invention includes the steps of: detecting animage of light shifting in association with a movable body displaced bya three-dimensional operation; determining a first direction outputamount and a second direction output amount from the shift of the imageof the light according to a two-dimensional displacement among thedisplacement by the three-dimensional operation; determining a thirddirection output amount from a change of the amount of the lightaccording to a remaining one-directional displacement; and calculating adirection and amount of the three-dimensional operation from the firstdirection output amount, the second direction output amount, and thethird direction output amount.

Alternatively, the input processing method for an input device for acomputer of the present invention includes the steps of: detecting animage of light shifting in association with a movable body displaced bya three-dimensional operation by a user; determining a first directionoutput amount and a second direction output amount from the shift of theimage of the light according to a two-dimensional displacement among thedisplacement by the three-dimensional operation; determining a thirddirection output amount from a change of the amount of the lightaccording to a remaining one-directional displacement; calculating adirection and amount of the two-dimensional operation from the firstdirection output amount and the second direction output amount; andjudging ON/OFF for a click function from the third direction outputamount.

In the above input device, when the operation section is tilted in adirection where the user desires to shift the cursor, light emitted fromthe light emitting element is reflected by the reflection plate andreaches the light receiving element. The light receiving element outputsa current corresponding to the tilt status of the operation section tothe output means. The output means calculates a value based on theoutput of the light receiving element and outputs the calculated resultscorresponding to the tilt direction and amount of the operation sectionto a control circuit of the computer body as an x direction output and ay direction output.

The computer body calculates the shift direction and speed of the cursorbased on the positional information and shifts the cursor on the displayunder the calculated conditions.

The entire output amount from the light receiving element changes bypressing the operation section. By detecting this change and outputtingan ON signal to the computer body, the operation section can be providedwith the click function.

In the above input device, when light emitted from the light sourcereaches the PSDs (position sensitive detectors) after being reflected bya finger tip and the like or directly, each of the PSDs outputs acurrent corresponding to the light incident position thereon. The outputmeans calculates values based on the output currents from the PSDs andoutputs the calculated results to the computer body as screen inputinformation.

The computer body determines the shift direction and speed of the cursorbased on the screen input information, so as to shift the cursor on thedisplay. Alternatively, a line is drawn according to the movement of thelight source, so as to display a character, a code, and the like on thescreen.

In the above input device, when the operation section is operatedforward, backward, leftward, rightward, upward, and downward in adirection where the user desires to move a cursor on a screen, lightemitted from the light emitting element reaches the PSDs after beingreflected by the operation section. The PSDs output currentscorresponding to the tilt status and the vertical position of theoperation section. The output means calculates values based on theoutputs of the PSDs and outputs the calculated results corresponding tothe tilt direction and amount of the operation section to the computerbody as an x direction output, a y direction output, and a z directionoutput.

The computer body calculates the shift direction and speed of the cursorbased on the three-dimensional positional information, so as to shiftthe cursor on the display three-dimensionally.

In the above input device, when the movable section is operated by theuser and displaced, the displacement is detected by the detectorcomposed of the light emitting element, the light receiving element, andthe like. In other words, the image of light from the light emittingelement shifts in association with the displacement of the movable body.This shift of the light image is detected by the light receivingelement. The direction of the load applied to the movable body isrepresented by the two crossing axial directions, a vector of the axialdirection outputs is obtained, and the direction and amount of theoperation is calculated from the synthesized vector. Based on thecalculated results, the shift direction and speed of the cursor on thedisplay is determined. Thus, the cursor shift according to the operationof the movable body is realized.

The above input device can adopt the detection by a non-contact opticalmethod, which provides high reliability and durability. Further, whenthe input device is disposed in a space surrounded by keys of thekeyboard, space savings can be realized. Alternatively, when the deviceis large enough to be handled with the palm of the user and is disposedseparately from the corresponding apparatus such as a computer,operability as high as that provided by the mouse can be obtained. Sincethis type of the input device is not required to be moved on a plane,unlike in the case of the mouse, space savings can be realized.

In the above input device, when a load is applied to the movable sectionin three dimensions to displace the movable section three-dimensionally,light emitted from the light emitting element reaches the lightreceiving element after being restricted by a light shader. The receivedlight image moves on the light receiving element in association with thedisplacement of the movable section. In other words, the light imagemoves on the light receiving element for the two-dimensionaldisplacement of the movable section. Based on this shift, thetwo-dimensional direction outputs, i.e., the first and second directionoutputs can be obtained. As for the displacement of the movable sectionin the third direction, the amount of light received by the lightreceiving element changes because the light shader restricts the opticalpath. This change of the light amount is used to determine the thirddirection output. The direction and amount of the three-dimensionaloperation are then calculated based on these three direction outputs.The calculated results are then given to the apparatus such as acomputer so as to shift a cursor or the like on a display.

A click function can be realized by generating an ON signal or an OFFsignal based on the amount of the third-dimensional direction output andinputting the ON or OFF signal into the apparatus such as a computer.Thus, a multi-functional input device can be realized.

Thus, the invention described herein makes possible the advantages of(1) providing an input device for a computer with high durability andreliability which does not require a large operation space and does notinclude a mechanical operation portion, (2) providing an input devicefor a computer allowing for three-dimensional image input operation, (3)providing a non-contact type input device with high reliability anddurability having an operability as high as that of a mouse, (4)providing an input processing method using such an input device, and (5)providing an input device for a computer or the like having multiplefunctions for input operation such as a three-dimensional input functionand a click function.

These and other advantages of the present invention will become apparentto those skilled in the art upon reading and understanding the followingdetailed description with reference to the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of a first example of the input deviceaccording to the present invention.

FIG. 2 is a sectional view of an optical sensor according to the presentinvention.

FIG. 3 is a block diagram of the input device according to the presentinvention.

FIG. 4 is a view showing the position of the input device according tothe present invention.

FIG. 5 is a view showing optical paths of light emitted from an lightemitting element according to the present invention.

FIG. 6 is a view for explaining the principle of a PSD according to thepresent invention.

FIG. 7 is a perspective view of an inner structure of a second exampleof the input device according to the present invention.

FIG. 8 is a sectional view of the input device according to the presentinvention.

FIG. 9 is a block diagram of the input device according to the presentinvention.

FIG. 10 is a sectional view of a third example of the input deviceaccording to the present invention.

FIG. 11 is a view showing the position of the input device according tothe present invention.

FIG. 12 is a block diagram of a fourth example of the input deviceaccording to the present invention.

FIG. 13 is a sectional view of a positional detection sensor accordingto the present invention.

FIG. 14 is a perspective view of a personal information apparatusprovided with the input device according to the present invention.

FIG. 15 is a view showing optical paths of light for a positionaldetection sensor according to the present invention.

FIG. 16 shows a view for explaining the detection principle of the inputdevice according to the present invention.

FIGS. 17A and 17B are a plan view and a front view, respectively,showing the detection range of the positional detection sensor accordingto the present invention.

FIG. 18 is a sectional view of a fifth example of the input deviceaccording to the present invention.

FIGS. 19A and 19B are a sectional view and a plan view, respectively, ofan optical sensor according to the present invention.

FIG. 20 is a block diagram of the input device according to the presentinvention.

FIG. 21 is a view showing optical paths of light from the light emittingelement obtained when an operation section is tilted.

FIG. 22 is a view showing optical paths of light from the light emittingelement obtained when an operation section is moved vertically.

FIG. 23 is a view for explaining the principle of a PSD according to thepresent invention.

FIG. 24 is a plan view of an optical sensor of an alternative exampleaccording to the present invention.

FIG. 25 is a sectional view of a sixth example of the input deviceaccording to the present invention.

FIGS. 26A and 26B are a top view and a side view, respectively, showingthe inside of the input device according to the present invention.

FIG. 27 shows the profile of the input device according to the presentinvention.

FIG. 28 is a perspective view of the input device according to thepresent invention.

FIG. 29 is a perspective view of an apparatus provided with the inputdevice according to the present invention.

FIGS. 30A and 30B are a top view and a side view, respectively, showingthe position of the input device on a keyboard according to the presentinvention.

FIGS. 31A, 31B, and 31C show views of a movable body where thereflection surface is flat, molded with a rigid resin, and curved,respectively.

FIG. 32 shows an arrangement of a quartered photodiode according to thepresent invention.

FIG. 33 is a block diagram of the input device according to the presentinvention.

FIG. 34 shows a configuration of a signal processing circuit accordingto the present invention.

FIG. 35 is a view showing the displacement of the input device accordingto the present invention.

FIG. 36 is a view showing optical paths of the input device according tothe present invention.

FIGS. 37A and 37B are views showing the shift of a light image when thedisplacement is around the X axis and the Y axis, respectively.

FIG. 38 shows the relationship between the X-axis direction output andthe rotational angle.

FIG. 39 shows the relationship between the Y-axis direction output andthe rotational angle.

FIG. 40 shows a vector of the X-axis and Y-axis direction outputs.

FIG. 41 shows the simulation results of the relationship between theX-axis direction output and the rotational angle.

FIG. 42 shows the simulation results of the relationship between theY-axis direction output and the rotational angle.

FIG. 43 schematically shows a configuration of a seventh example of theinput device according to the present invention;

FIGS. 44A and 44B are a perspective view and a sectional view,respectively, of an improved one-side division type PSD according to thepresent invention.

FIGS. 45A and 45B are a view for explaining the positional detectionmethod of the improved one-side division type PSD, and a view showing avector of the X-axis and Y-axis direction outputs, respectively.

FIGS. 46A and 46B show an arrangement of a light receiving element andoptical paths, respectively, of an eighth example of the input deviceaccording to the present invention.

FIG. 47 shows a configuration of a signal processing circuit accordingto the present invention.

FIGS. 48A and 48B are views showing the shift of a light image when thedisplacement is around the X axis and the Y axis, respectively.

FIGS. 49A, 49B, and 49C show the relationship between the X-axisdirection output and the rotational angle, the relationship between theY-axis direction output and the rotational angle, and a vector of theX-axis and Y-axis direction outputs, respectively.

FIG. 50 is a sectional view of a ninth example of the input deviceaccording to the present invention.

FIG. 51 is a sectional view of an input device employing a tilt sensorwithout a lens according to the present invention.

FIG. 52 is a schematic sectional view of a tenth example of the inputdevice according to the present invention.

FIGS. 53A and 53B are a view for explaining the detection principle anda view showing the displacement of a light image on a light receivingelement, respectively.

FIG. 54 is a schematic sectional view of an input device where a lightemitting element and a light receiving element face each other accordingto the present invention.

FIG. 55 is a schematic sectional view of an eleventh example of theinput device according to the present invention.

FIG. 56 shows the operation of the input device according to the presentinvention.

FIG. 57 is a sectional view of a twelfth example of the input deviceaccording to the present invention.

FIGS. 58A and 58B are a top view and a side view of the inside of theinput device according to the present invention.

FIG. 59 is a perspective view of the input device according to thepresent invention.

FIGS. 60A, 60B, and 60C show the displacement of a movable body when noload is applied, when load is applied in a two-dimensional direction,and when load is applied in the Z-axis direction, respectively.

FIG. 61 shows a movable body where the reflection surface is formed of arigid material according to the present invention.

FIGS. 62A to 62E show alternative movable bodies having differentelastic structures according to the present invention.

FIGS. 63A to 63D show alternative movable bodies having differentelastic structures according to the present invention.

FIG. 64 shows a movable body having an elasticity provided by the shapeof the movable section according to the present invention.

FIGS. 65A to 65D show alternative elastic sections according to thepresent invention.

FIG. 66 shows a movable body provided with an elastic structure having aspring according to the present invention.

FIG. 67 shows an arrangement of a quartered photodiode according to thepresent invention.

FIGS. 68A and 68B are a view showing a restriction of optical paths by alight shader, and a plan view of the light shader, respectively,according to the present invention.

FIG. 69 is a block diagram of the input device according to the presentinvention.

FIG. 70 shows a configuration of an analog signal processing circuitsection according to the present invention.

FIG. 71 shows optical paths in the output device according to thepresent invention.

FIGS. 72A and 72B show the displacement of a reflection surface aroundthe X-axis direction and the shift of the light image caused by thedisplacement shown in FIG. 72A, respectively.

FIGS. 73A and 73B show the displacement of a reflection surface aroundthe Y-axis direction and the shift of the light image caused by thedisplacement shown in FIG. 73A, respectively.

FIG. 74 shows the relationship between the X-axis direction output andthe rotational angle according to the present invention.

FIG. 75 shows the relationship between the Y-axis direction output andthe rotational angle according to the present invention.

FIG. 76 shows a vector of the X-axis and Y-axis direction outputs.

FIG. 77 shows optical paths obtained when a movable body is displaced inthe Z-axis direction according to the present invention.

FIGS. 78A and 78B show the simulation results of the relationshipbetween the X-axis direction output and the rotational angle and therelationship between the Y-axis direction output and the rotationalangle, respectively.

FIG. 79 shows the simulation result when a movable body is displaced inthe Z-axis direction.

FIG. 80 is a sectional view of a movable body having a clicking touchaccording to the present invention.

FIG. 81 is a sectional view of another movable body having a clickingtouch according to the present invention.

FIGS. 82A and 82B are sectional views of a movable body with a clickingmeans according to the present invention.

FIG. 83 is a sectional view of another movable body with a click meansaccording to the present invention.

FIG. 84 is a sectional view of a thirteenth example of the input deviceaccording to the present invention.

FIGS. 85A and 85B are a schematic view of the input device when no loadis applied and a view showing a light image on a light receiving elementwhen the input device is in the state of FIG. 85A according to thepresent invention.

FIGS. 86A and 86B are a schematic view of the input device when a loadis applied in a two-dimensional direction and a view showing a lightimage on a light receiving element when the input device is in the stateof FIG. 86A according to the present invention.

FIGS. 87A and 87B are a schematic view of the input device when a loadis applied in the Z-axis direction and a view showing a light image on alight receiving element when the input device is in the state of FIG.87A according to the present invention.

FIGS. 88A and 88B are a schematic view of the input device when amovable section is displaced three-dimensionally and a view showing alight image on a light receiving element when the input device is in thestate of FIG. 88A according to the present invention.

FIGS. 89A and 89B are a view showing the distance between the lightemitting element and the pinhole and the relationship between thedistance between the light emitting element and the pinhole and therelative received light amount according to the present invention.

FIGS. 90A and 90B show the difference in the X-axis or Y-axis directionoutput between when a load in the Z-axis direction is present and whenit is not present, and the X-axis or Y-axis direction output before andafter the correction, respectively.

FIG. 91 is a perspective view of a personal computer provided with aconventional track ball.

FIG. 92 is a view for explaining the operational principle of the trackball.

FIG. 93 is a perspective view of a conventional mouse.

FIG. 94 is a sectional view of the mouse.

FIGS. 95A and 95B are perspective views of a conventional pointing stickand the interior of the pointing stick, respectively.

FIGS. 96A and 96B are perspective views of a personal computer providedwith the pointing stick.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

(Example 1)

A first example of the input device according to the present inventionwill be described with reference to FIGS. 1 to 6.

FIGS. 1, 2, and 3 schematically show a configuration of an input device100 of Example 1. The input device 100, which is used for a computer orthe like, includes a reflection type optical sensor 32, an inputoperation section 33 disposed above the optical sensor 32 in such amanner that it can be tilted relative to the optical sensor 32, and anoutput circuit 35 (FIG. 3). The reflection type optical sensor 32includes a light emitting diode (LED) 30 as a light emitting element anda both-side division type position sensitive detector (PSD) 31 fortwo-dimensional position detection as a light receiving element. The PSD31 is described in more detail below. The output circuit 35 detects thetilt of the operation section 33 caused when no load is applied fromoutside to the operation section 33 based on an output signal of the PSD31 and outputs the detected results to a computer body as positionalinformation. The input device 100 with the above configuration isdisposed on a corner of a keyboard 36 of a personal computer, forexample, so that the operation section 33 protrudes from the plane ofthe keyboard 36, as shown in FIG. 4.

The configuration of the optical sensor 32 is shown in FIG. 2. Theoptical sensor 32 further includes a printed board 40 on which the LED30 and the PSD 31 are mounted with a space therebetween and alight-shading resin case 41 covering the printed board 40. The opticalsensor 32 is secured inside the keyboard 36 with a screw or the like. Aconnector 42 for connection with an internal circuit of the computerbody is attached to the printed board 40. The LED 30 is inclined towardthe PSD 31 and is surrounded by an oblique wall 43 extending from thecase 41 so that light emitted from the LED 30 is prevented from beingdirectly incident on the PSD 31. On the top surface of the case 41 areprovided an emitted light pass hole 44 for allowing light emitted fromthe LED 30 to pass therethrough and a reflected light pass hole 46 forallowing only light reflected by a reflection plate 45 to passtherethrough to be incident on the PSD 31. The reflected light pass hole46 is a conical shaped hole having a predetermined size and is formedabove the PSD 31. The case 41 helps prevent dust from attaching to thePSD 31.

The operation section 33 as shown in FIG. 1 includes a dome 47 made of alight-shading resin and the reflection plate 45 disposed inside of thedome 47. The reflection plate 45 has a mirror bottom surface. Aprotrusion 48 is formed on the zenith of the dome 47 for providing aposition where a finger is put. A ring-shaped elastic rubber support 49is secured to the outer circumference of the lower portion of the dome47. The support 49 is fitted in a hole 50 formed at the top surface ofthe keyboard 36. With this configuration, the operation section 33 canbe tilted forward, backward, rightward, and leftward, as well as beingmoved upward and downward.

Now, the operational principle of the PSD 31 will be described. The PSD31 is a sensor utilizing a silicon photodiode for detecting the positionof a light spot. When light is incident on the PSD 31 to form a spotthereon, electric charges of an amount in proportion to the light energyare generated at the incident position. The electric charges are outputfrom an electrode as a photoelectric current. The photoelectric currentis divided inversely proportionally to the distance between the incidentposition and the electrode before being output from the electrode. Thelight incident position can thus be determined.

Accordingly, the incident position on the PSD 31 of light which has beenemitted from the LED 30 and arrived at the PSD 31 after being reflectedby the reflection plate 45 is determined. As shown in FIG. 5, the lightemitted from the LED 30 has a fixed divergent angle. The law ofreflection defines that the angle of incident light and the angle ofreflected light to and from the mirror face of the reflection plate 45are the same, and that the incident light, the reflected light, and thenormal at the reflection point on the mirror surface are in the sameplane. By using this law, the angle of light passing through thereflected light pass hole 46 can be determined according to the angle ofthe reflection plate 45, i.e., the tilt of the operation section 33.Once the angle of light passing through the reflected light pass hole 46is determined, the light incident position on the PSD 31 is determined.For example, when the reflection plate 45 is at a tilt A, light a isreflected by the reflection plate 45 and is incident on the PSD 31.Likewise, when the reflection plate 45 is at a tilt B, light b isreflected by the reflection plate 45 and is incident on the PSD 31. Whenthe reflection plate 45 is at a tilt C, light c is reflected by thereflection plate 45 and is incident on the PSD 31. Thus, the lightincident position on the PSD 31 varies depending on the tilt of thereflection plate 45.

Referring to FIG. 6, assume that reflected light from the reflectionplate 45 passes through the reflected light pass hole 46 and is incidenton a point P on the PSD 31 having an effective light receiving size of L(mm)×L (mm). Output currents I₁ and I₂ in the x direction obtained fromthe PSD 31 are expressed by:

    I.sub.1 =I.sub.0 ×x.sub.1 /L                         (1)

    I.sub.2 =I.sub.0 ×(L-x.sub.1)/L                      (2)

Output currents I₃ and I₄ in the y direction obtained from the PSD 31are expressed by:

    I.sub.3 =I.sub.0 ×y.sub.1 /L                         (3)

    I.sub.4 =I.sub.0 ×(L-y.sub.1)/L                      (4)

where I₀ is the electric charges generated at the point P incorrespondence with the incident light amount.

Here, from the above Formulae, I₁ /(I₁ +I₂) and I₃ /(I₃ +I₄), forexample, are expressed by:

    I.sub.1 /(I.sub.1 +I.sub.2)=(I.sub.0 ×x.sub.1 /L)/I.sub.0 =x.sub.1 /L (5)

    I.sub.3 /(I.sub.3 +I.sub.4)=(I.sub.0 ×y.sub.1 /L)/I.sub.0 =y.sub.1 /L (6)

Thus, by calculating the above formulae of the output currents of thePSD 31, an output corresponding to the position of light incident on thePSD 31 can be obtained. Also, as described above, when the direction andangle of the tilt of the reflection plate 45 varying in association withthe tilt of the operation section 33 are determined, the position oflight incident on the PSD 31 is determined. Accordingly, by calculatingI₁ /(I₁ +I₂) and I₃ /(I₃ +I₄), for example, using the outputs of the PSD31, outputs corresponding to the direction and angle of the tilt of theoperation section 33 can be obtained. I₁ /(I₁ +I₂) and I₃ /(I₃ +I₄)correspond to the tilt amounts of the operation section 33 in the x andy directions, respectively.

Referring to FIG. 3, the output circuit 35 is connected to a controlcircuit 51 incorporated in the computer body where the input device 100is disposed. The control circuit 51 includes, in addition to a CPU, aROM, a RAM, etc., a shifting section 52 for controlling the shift of thecursor on a display of the computer body based on the positionalinformation corresponding to the tilt of the operation section 33.

Referring to FIG. 3, the output circuit 35 includes a signal processingcircuit section 53 and an A/D conversion section 54. The signalprocessing circuit section 53 calculates the tilt amount in the xdirection, I₁ /(I₁ +I₂), and the tilt amount in the y direction, I₃ /(I₃+I₄), based on the output currents of the PSD 31. The A/D conversionsection 54 converts the analog values calculated by the signalprocessing circuit section 53 into digital values and outputs them tothe control circuit 51 as an x direction output and a y directionoutput. The x direction output and the y direction output are outputfrom individual output terminals of the A/D conversion section 54 asparallel data. Alternatively, they may be output from a single outputterminal as serial data. The output circuit 35 also includes an LEDdriving circuit section 55 for driving the LED 30. The LED drivingcircuit section 55 controls the LED 30 so that the LED 30 always emitslight as long as the power switch of the computer body is on.

Based on the positional information corresponding to the tilt amount ofthe operation section 33 in the x and y directions, i.e., the xdirection output and the y direction output, the shifting section 52 ofthe control circuit 51 calculates the shift direction and speed of thecursor corresponding to the tilt amount of the operation section 33, soas to shift the cursor on the screen of the display based on thecalculated results.

The cursor shift by the input device 100 with the above configurationwill be described. As shown in FIG. 1, a finger is positioned on theprotrusion 48 so as to tilt the operation section 33 in a direction inwhich the user wishes to shift the cursor on the screen. Light emittedfrom the LED 30 is reflected by the reflection plate 45, and only thereflected light which passes through the reflected light pass hole 46reaches the PSD 31. The PSD 31 outputs a value corresponding to thelight incident position on the PSD 31. The output circuit 35 calculatesthe tilt amounts in the x and y directions based on the value outputfrom the PSD 31 and outputs the calculated results corresponding to thetilt direction and angle of the operation section 33, i.e, the xdirection output and the y direction output, to the control circuit 51of the computer body.

In the computer body, the control circuit 51 calculates the shiftdirection and speed of the cursor based on the positional information(i.e., the x direction output and the y direction output), and shiftsthe cursor on the screen based on the calculated results. For example,when the operation section 33 is tilted a little in the +x directionwith no tilt in the y direction, the shift direction and speed of thecursor are determined based on the tilt amounts in the x direction andthe y direction. Thus, the cursor is shifted in the +x direction at alow speed. When the operation section 33 is tilted largely in the +xdirection with no tilt in the y direction, the cursor is shifted in the+x direction at a high speed. When the tilts are small and the same inthe x and y directions, the cursor is shifted in the 45° direction at alow speed.

(Example 2)

A second example of the input device according to the present inventionwill be described with reference to FIGS. 7 to 9.

Referring to FIGS. 7 and 8, an input device 200 of Example 2 includes anoptical sensor 60 having an LED 30 and four phototransistors PT1 to PT4as light receiving elements. The LED 30 is positioned at the center ofthe top surface of a holder 61 of which lead frame is insert-molded. Thephototransistors PT1 to PT4 are disposed on the holder 61 concentricallyaround the LED 30 and along the x and y directions. As shown in FIG. 8,the holder 61 is attached to the bottom edge of a dome 47 of anoperation section 33. A ring light-shading wall 62 is disposed on theholder 61 to surround the LED 30 so that light emitted from the LED 30is prevented from being directly incident on the phototransistors PT1 toPT4. An external wall 63 is also formed so that external light isprevented from being directly incident on the phototransistors PT1 toPT4. The remaining sections of the input device 200 are the same asthose described in Example 1.

When the light emitted from the LED 30 is reflected by a reflectionplate 45 and incident on the phototransistors PT1 to PT4, thephototransistors PT1 to PT4 output currents I₁, I₂, I₃, and I₄,respectively, corresponding to the received light amounts. The currentsI₁, I₂, I₃, and I₄ are sent to a signal processing circuit section 53 ofan output circuit 35 as shown in FIG. 9. The signal processing circuitsection 53 calculates I₁ /I₂ as an output current ratio in the xdirection and I₃ /I₄ as an output current ratio in the y direction, andoutputs the calculated results to a control circuit 51 of a computerbody having the same configuration as that of Example 1, through an A/Dconversion section 54, as an x direction output and a y directionoutput. The output current ratios in the x direction and in the ydirection may also be I₁ /(I₁ +I₂) and I₃ /(I₃ +I₄), respectively.

The shift of a cursor on a computer display screen is controlled by thecontrol circuit 51 of the computer body based on the positionalinformation output from the output circuit 35, i.e., the x directionoutput and the y direction output from the A/D conversion section 54.For example, when the operation section 33 is not tilted as shown inFIG. 7, light from the LED 30 reflected by the reflection plate 45 issubstantially equally incident on the four transistors PT1 to PT4. Thus,the values of the output currents I₁, I₂, I₃, and I₄ are substantiallythe same. In this case, the cursor does not shift.

When the operation section 33 is tilted in the -x direction (thedirection indicated by the arrow in FIG. 7), the reflection plate 45tilts, and as a result, the output current of the phototransistor PT1decreases, while that of the phototransistor PT2 increases. Bycalculating the output current ratio of the phototransistor PT1 to thephototransistor PT2, an output corresponding to the amount of tilt ofthe operation section 33 in the x direction can be obtained. Likewise,by calculating the output current ratio of the phototransistor PT3 tothe phototransistor PT4, an output corresponding to the amount of tiltof the operation section 33 in the y direction can be obtained. Based onthe thus-obtained positional information, the cursor shifts on thescreen in the -x direction at a speed corresponding to the amount oftilt.

(Example 3)

A third example of the input device according to the present inventionwill be described with reference to FIGS. 10 and 11.

An input device 300 of Example 3 includes an operation section 333, andan optical sensor 32 having the same configuration as that of Example 1.As shown in FIG. 10, the operation section 333 includes a stick section65 and a reflection plate 45 attached to the bottom end of the sticksection 65. A rubber ring support 66 is secured to the circumference ofthe stick section 65. The support 66 is fitted in a hole 50 formed onthe surface of a keyboard 36, as shown in FIG. 11, so as to secure theinput device 300 to the keyboard 36 of a computer. With thisconfiguration, the operation section 333 can be tilted forward,backward, rightward, and leftward, as well as being shifted upward anddownward. The remaining sections are the same as those described inExample 1, and the same functions and effects can be obtained.

In Examples 1 to 3, the operation section 33 or 333 is movable upwardand downward as described above. When the operation section 33 or 333 ispressed downward, the distance between the reflection plate 45 and theoptical sensor 32 is decreased, and thus the total output current of thelight receiving elements, I₁ +I₂ +I₃ +I₄ increases. This increase of theoutput current may be detected by the output circuit 35 and sent to thecontrol circuit 51 as an ON signal, so that the operation sections 33and 333 can be provided with a function of click button.

As the size of computers is increasingly made smaller, portablecomputers with a battery embedded therein become more popular. In orderto reduce power consumption as is required for such small-size portablecomputers, it is advisable that the LED driving circuit section 55should control the LED 30 to emit light intermittently like a pulse. Insuch a case, the output currents from the light receiving elements canbe detected in synchronization with the light emission of the LED 30.With this operation, an influence of turbulence such as noise can beeliminated, and thus the reliability of the input device can beenhanced.

The above examples can be modified and changed. For example, a laserdiode or a fluorescent display tube may be used as the light emittingelement. A photodiode may be used as the light receiving element . InExample 2, the number of phototransistors is not limited to four, butthree or more phototransistors can be used. The larger the number of thephototransistors is, the higher the detection precision is.

As is apparent from the above description, in the above examples, theoperation section is tilted, and the tilt is detected by the opticalsensor. The cursor is shifted on the screen based on the positionalinformation as the detected results. Accordingly, an input deviceemploying a non-contact optical method without the need for a mechanicaloperation section can be realized. According to such an input device,malfunction does not occur due to the build up of dust coming fromoutside. Thus, the reliability and durability can be enhanced, and thelife of the input device can be prolonged. The operation section of theinput device is positioned on the top surface of the computer body andno space is additionally required. Accordingly, the computer can be usedat any location without the need for a separation operation surface fora mouse, for example. The input device of the present invention can betherefore applied to small-size computers and portable informationapparatuses. Moreover, in the case where the operation section is of adome shape as in Examples 1 and 2, the cursor can be shifted using amanner similar to rotating a ball as in the case of the conventionaltrack ball. In the case where the operation section has a stick shape asin Example 3, the cursor can be shifted by way of tilting the stick.Thus, in both cases, excellent operability can be provided.

The operation section is secured to the computer body via the elasticsupport. Accordingly, the operation section can be pressed to be closerto the optical sensor. This makes it possible to provide the operationsection with the click function in addition to the cursor shiftingfunction, realizing a multi-functional input device. Since a clickbutton is not additionally required, the computer can be furtherminiatualized.

The light emitting element can emit light intermittently. Accordingly,the current consumption can be reduced compared with the case wherelight is always emitted. As a result, the life of a battery and the likecan be prolonged, and thus an input device more suitable for small-sizecomputers and portable information apparatuses can be obtained.

(Example 4)

A fourth example of the input device according to the present inventionwill be described with reference to FIGS. 12 to 17B.

As shown in FIG. 12, an input device 400 of Example 4 includes a lightemitting element 430 as a light source, two two-dimensional PSDs 431 and432, and an output circuit 433. An LED is used, for example, as thelight emitting element 430. Each of the PSDs 431 and 432 outputs asignal to the output circuit 433 indicating the amount of light receivedthereby when it is irradiated with the light. The output circuit 433calculates screen input information based on the signals output from thePSDs 431 and 432, and outputs the results to a control circuit 450 of acomputer body.

As shown in FIG. 13, the light emitting element 430 and the PSDs 431 and432 are soldered to a printed board 435 so that the light emittingelement 430 is located at the center and the PSDs 431 and 432 arelocated on the both sides of the light emitting element 430, thusconstituting a positional detection sensor 436. An IC 437 usedexclusively for control is attached by direct bonding to the surface ofthe printed board 435 opposite to the surface where the light emittingelement 430 and the PSDs 431 and 432 are soldered. The IC 437 isconnected to the light emitting element 430 and the PSDs 431 and 432. Aconnector 438 connected to the control circuit 450 of the computer bodyis also attached to the surface of the printed board 435 where the IC437 is attached.

The printed board 435 is covered with a holder 439 made of alight-shading resin. The holder 439 has an emitted light pass hole 440,a first reflected light pass hole 441, and a second reflected light passhole 442 at positions on the top surface thereof corresponding to thelight emitting element 430, the PSDs 431 and 432, respectively. Alight-shading wall 443 extends from the inner upper surface of theholder 439 toward the printed board 435 so as to surround the lightemitting element 430. Light emitted from the light emitting element 430is thus prevented from being directly incident on the PSDs 431 and 432.

As shown in FIG. 14, the holder 439 where the positional detectionsensor 436 is incorporated is mounted on the front side of the computerbody (a personal information apparatus in this example) so that thelight emitting element 430 and the PSDs 431 and 432 face outside. Theemitted light pass hole 440 is of a conical shape with a large openingarea so that the emitted light can diverge in a conical fashion. Thereflected light pass holes 441 and 442 are also of a conical shape witha predetermined opening area which is smaller than that of the emittedlight pass hole 440 so as to prevent turbulent light from enteringthrough the holes. The attachment of dust to the PSDs 431 and 432 isprevented by the holder 439.

The output circuit 433 (FIG. 12) is incorporated in the exclusive IC 437and connected to the control circuit 450 incorporated in the computerbody. The control circuit 450 includes, in addition to a CPU, a ROM, aRAM, etc., a shifting section 451 for controlling the shift of a cursoron a display of the computer body from the screen input informationbased on the signals output from the PSDs 431 and 432.

The output circuit 433 receives output currents I₁, I₂, I₃, and I₄ ofthe PSDs 431 and 432 as shown in FIG. 12. The output circuit 433includes a signal processing circuit section 452 for calculating I₁ /I₂and I₃ /I₄ and an A/D conversion section 453. The A/D conversion section453 converts the calculated analog results from the signal processingcircuit section 452 into digital values, and outputs the digital valuesto the control circuit 450 as the x direction output and the y directionoutput. In Example 4, the x direction output and the y direction outputare output from the A/D conversion section 453 as parallel data.Alternatively, they may be output from a single output terminal asserial data. The output circuit 433 further includes an LED drivingcircuit section 454 for driving the light emitting element 430. The LEDdriving circuit section 454 controls the light emitting element 30 sothat the light emitting element 30 always emits light as long as thepower switch of the computer body is on.

The shifting section 451 of the control circuit 450 calculates the shiftdirection and speed of the cursor from the screen input information,i.e., the x direction output and the y direction output of the outputcircuit 433, so as to shift the cursor on the screen.

Referring to FIGS. 14 and 15, the cursor is shifted on the screen bymoving a movable means 455 such as a finger tip or a pen tip within theexpanse of the light emitted from the light emitting element 430. Withthe movable means 455 within an expanse S of the light from the lightemitting element 430, the light from the light emitting element 430 isreflected by the movable means 455 and the reflected light is incidenton the PSDs 431 and 432. When the movable means 455 is at positions A,B, C, and D, the incident angles of the reflected light to the PSDs 431and 432 are different from one another. Thus, the position of themovable means 455 can be detected by using the two PSDs 431 and 432.

The detection principle will be described in detail. The PSDs 431 and432 are positional sensitive detectors of the same type as thatdescribed in Example 1. The light incident position can be determined byusing these sensors.

Referring to FIG. 16, the following are defined:

point P: position of the movable means 455

(X, Y): coordinate of point P

(O, O): coordinate of the first reflected light pass hole 441

(A, O): coordinate of the second reflected light pass hole 442

θ₁ : angle of light incident on the PSD 431 from point P

θ₂ : angle of light incident on the PSD 432 from point P

B: distance between the reflected light pass holes and the correspondingPSDs

C: positions of the PSDs

X₁, X₂ : light incident positions on the PSDs 431 and 432

L: length of the light receiving portion of the PSDs

I₁, I₂ : output currents of the PSD 431

I₃, I₄ : output currents of the PSD 432

Under the above definitions, the relationship between the output currentand the light incident position of the PSD 431 is expressed by:

    I.sub.1 =I.sub.0 ×(L-X.sub.1)/L                      (7)

    I.sub.2 =I.sub.0 ×X.sub.1 /L                         (8)

(where I₀ =I₁ +I₂)

From formulae (7) and (8), the following is obtained.

    X.sub.1 =L×I.sub.2 /(I.sub.1 +I.sub.2 )=L/(I.sub.1 /I.sub.2 +1) (9)

Similarly, the following is obtained for the PSD 432:

    X.sub.2 =L×I.sub.4 /(I.sub.3 +I.sub.4)=L/(I.sub.3 /I.sub.4 +1) (10)

Then, the relationship between the light incident angle and the lightincident position of the PSD 431 is obtained. Since D₁ =B/tan θ₁,

    X.sub.1 =L-C-D.sub.1 =L-C-B/tan θ.sub.1.

Accordingly,

    B/tan θ.sub.1 =L-C-X.sub.1 tan θ.sub.1 =B/(L-C-X.sub.1) (11)

Similarly, the following is obtained for the PSD 432:

    tan θ.sub.2 =B/(L-C-X.sub.2)                         (12)

The relationship between the coordinate of the movable means 455 and thelight incident angle is expressed by:

    tan θ.sub.1 =Y/X                                     (13)

    tan θ.sub.2 =Y/(A-X)                                 (14)

Y is deleted from Formulae (13) and (14).

    X×tan θ.sub.1 =(A-X)×tan θ.sub.2 X=A×tan θ.sub.2 /(tan θ.sub.1 +tan θ.sub.2)     (15)

X of Formula (13) is substituted as follows:

    Y=A×tan θ.sub.1 ×tan θ.sub.2 /(tan θ.sub.1 +tan θ.sub.2)                                       (16)

The relationship between the position of the movable means 455 and thelight incident positions on the PSD 431 or 432 is expressed as followsby combining Formula (15) with Formulae (11) and (12): ##EQU1##Similarly, Formula (16) is combined with Formulae (11) and (12) asfollows: ##EQU2## In Formulae (17) and (18), A, B, C, and L areconstants; X₁ and X₂ are determined by the current ratios for the PSDs431 and 432, I₁ /I₂ and I₃ /I₄, as expressed in Formulae (9) and (10),respectively. Since the current ratios, I₁ /I₂ and I₃ /I₄ can becalculated by the signal processing circuit section 452 shown in FIG.12, the coordinate of the movable means 455 can be calculated.

In the input device 400 having the above configuration, the movablemeans 455 such as a finger tip is placed within the expanse S of thelight emitted from the light emitting element 430 disposed at the frontside of the computer 444. The light emitted from the light emittingelement 430 is reflected by the movable means 455. Part of the reflectedlight passes through the reflected light pass holes 441 and 442 so as toreach the PSDs 431 and 432, respectively. The PSDs 431 and 432 outputcurrents corresponding to the light incident positions thereon to theoutput circuit 433. The output circuit 433 calculates the current ratiosI₁ /I₂ and I₃ /I₄, converts the calculated results into digital signals,and outputs the digital signals to the control circuit 450 incorporatedin the computer body 444 as the x direction output and the y directionoutput, respectively.

The control circuit 450 of the computer body 444 always monitors theoutputs of the output circuit 433. The control circuit 450 calculatesthe shift direction and speed of the cursor based on a variation in thecoordinate of the movable means 455, so as to shift the cursor on thescreen under the calculated conditions. For example, when the movablemeans 455 moves rightward from the initial position, the cursor shiftsrightward. When the movable means 455 moves forward, the cursor shiftsdownward, while when the former moves backward, the latter shiftsupward. When the movable means 455 moves rapidly, the cursor shiftsrapidly, while when the former moves slowly, the latter shifts slowly.

In the above example, only the position of the movable means 455 withrespect to the X-Y coordinate was detected. The light from the lightemitting element 430, however, also expands in the Z direction as shownin FIG. 17B. If the position in the Z coordinate is additionallydetected, the control circuit 450 will be provided with an inputfunction capable of inputting characters, codes, figures, and the like.Characters and the like can be formed on the screen by moving themovable means 455 in the X and Y directions within the expanse S of thelight from the light emitting element 430, detecting the start point andthe end point of the movement from the outputs of the PSDs 431 and 432,and drawing a line between the start point and the end point. The startpoint and the end point may be determined in the following manner: Apoint where the movable means 455 moves upward in the Z direction isdefined as the end point, while a point where the movable means 455moves downward in the Z direction is defined as the start point. Byadopting this method, characters and the like can be input only bymoving the movable means 455 without key operation.

Incidentally, if an object other than the movable means 455 such as afinger tip is present in front of the input device 400, light reflectedby such an object may be incident on the PSDs 431 and 432. This maycause unintended cursor shifting and character drawing on the screen. Inorder to prevent these problems and enhance the usability of thecomputer, a switch or a command may be provided for switching between amode where the input device 400 is used and a mode where it is not used.

Example 4 can be modified and changed. For example, the LED drivingcircuit section 454 may control the light emitting element 430 to emitlight intermittently like a pulse. Thus, a computer with low powerconsumption can be realized

The position of the positional detection sensor 436 is not limited tothe side face of the computer body 444. Instead, the positionaldetection sensor 436 may be disposed on the top surface of the computerbody 444. Also, instead of incorporating the light emitting element 430and the PSDs 431 and 432 in the computer body 444, only two PSDs may beincorporated in the computer body. A light source such as an LED and alamp may be mounted on the movable means, and light from the lightsource may be directly incident on the PSDs. Further, for the input ofcharacters and the like, the start point and the end point may bedetermined by key operation.

As is apparent from the above description, in Example 4, the cursor canbe shifted on the screen of the display of the computer body, orcharacters, codes, figures, and the like can be displayed on the screenbased on the output signals from the PSDs obtained when the lightemitted from the light source is incident on the PSDs. Accordingly, theinput device of the present invention employs a non-contact opticalmethod and no mechanical operation section is included. This inputdevice is therefore excellent in durability and reliability, has a longlife, and can be produced at low cost.

Since the light source and the PSDs can be formed integrally, the inputdevice can be made smaller. This reduces the area and volume occupied bythe input device in the computer body. Also, since an additional areafor input operation is not necessary, the size of the computer can befurther reduced. The input device of this example is therefore suitablefor portable personal information apparatuses. Because character inputoperation is possible, a conventional keyboard can be omitted. Thisfurther reduces the size of the computer.

(Example 5)

A fifth example of the input device according to the present inventionwill be described with reference to FIGS. 18 to 24. The input device ofExample 5 can input three-dimensional images into a display ofcomputers, wordprocessors, CAD terminals, computer game machines, andthe like.

FIGS. 18, 19A, 19B, and 20 schematically show an configuration of aninput device 500 of Example 5. The input device 500 includes areflection type optical sensor 533, an input operation section 534, andan output circuit 535. The reflection type optical sensor 533 includes alight emitting diode (LED) 530 as a light emitting element, and aboth-side division type two-dimensional PSD 531 and a one-dimensionalPSD 532 as the light receiving elements. The input operation section 534is disposed above the optical sensor 533 so that it can be tilted andmoved vertically (up and down relative to FIG. 18). The output circuit535 detects the tilt and the vertical position of the operation section534 from signals output from the PSDs 531 and 532, and outputs thedetected results to the computer body as three-dimensional positionalinformation. A shifting section 536 connected to the output circuit 535shifts a cursor on a display of the computer body three-dimensionallybased on the three-dimensional positional information obtained from theoutput circuit 535 indicating the tilt and the vertical position of theoperation section 534. The input device 500 is disposed on a corner of akeyboard 537 of a personal computer and the like so that the operationsection 534 protrudes from the keyboard 534.

Referring to FIG. 19A, the optical sensor 533 further includes a printedboard 540 and a case 541 made of a light-shading resin covering theprinted board 540. The LED 530 and the PSDs 531 and 532 are mounted onthe printed board 540 so that the PSDs 531 and 532 are located on bothsides of the LED 530. The case 541 is fitted in the keyboard 537 with ascrew or the like. Dust build up on the PSDs 531 and 532 is prevented bythe case 541. A connector 542 for connecting an internal circuit of thecomputer body is attached to the printed board 540.

As shown in FIG. 19A, the LED 530 is surrounded by a light-shading wall543 protruding from the case 541 so that light emitted from the LED 530will not be directly incident on the PSDs 531 and 532. The top surfaceof the case 541 has three holes formed therethrough: an emitted lightpass hole 544 located above the LED 530 for allowing light emitted fromthe LED 530 to pass therethrough; a reflected light pass hole 546located above the two-dimensional PSD 531 for allowing only lightreflected by a reflection plate 545 to be described later to be incidenton the two-dimensional PSD 531; and a reflected light pass hole 547located above the one-dimensional PSD 532. As shown in FIG. 19B, theemitted light pass hole 544 and the reflected light pass hole 546 arecircular in section, while the reflected light pass hole 547 isrectangular in section elongate in the direction perpendicular to theaxis of the one-dimensional PSD 532.

As shown in FIG. 18, the operation section 534 includes a stick section550 with a sphere at the top thereof and a mirror-like reflection plate545 attached integrally to the bottom end of the stick section 550. Arubber ring support 551 is secured to the circumference of the sticksection 550. The support 551 is fitted in a hole 552 formed at thesurface of a keyboard 537. With this configuration, the operationsection 534 can be tilted forward, backward, rightward, and leftward, aswell as being moved upward and downward.

In Example 5, the PSD for detecting the one-dimensional position and thePSD for detecting the two-dimensional position are used. The detectionprinciple is the same as that described in Example 1. Light is emittedfrom the LED 530 and arrives at the PSDs 531 and 532 after beingreflected by the reflection plate 545. The light incident positions onthe PSDs 531 and 532 can be determined based on the photoelectriccurrent output from the PSDs 531 and 532. As shown in FIG. 21, the lightemitted from the LED 530 has a fixed divergent angle. The law ofreflection defines that the angle of incident light and the angle ofreflected light to and from the reflection plate 545 are equal, and thatthe incident light, the reflected light, and the normal at theirradiation point on the mirror surface are in the same plane. By usingthis law, the angles of light passing through the reflected light passholes 546 and 547 can be determined according to the tilt and verticalposition of the reflection plate 545. Once the angles of light passingthrough the reflected light pass holes 546 and 547 are determined, thelight incident positions on the PSDs 531 and 532 are determined.

For example, when the reflection plate 545 is at a tilt A, the lightfrom the LED 530 is reflected by the reflection plate 545 as shown bysolid line in FIG. 21 and is incident on the PSDs 531 and 532. Likewise,when the reflection plate 545 is at a tilt B, the light is reflected bythe reflection plate 545 as shown by dotted line and is incident on thePSDs 531 and 532. Thus, the light incident positions vary depending onthe tilt of the reflection plate 545.

Further, the reflection plate 545 moves vertically as the operationsection 534 moves vertically. Accordingly, when the reflection plate 545is at a position C as shown in FIG. 22, the light is reflected by thereflection plate 545 as shown by the solid line and is incident on thePSDs 531 and 532. Likewise, when the reflection plate 545 is at aposition D, the light is reflected by the reflection plate 545 as shownby the broken line in FIG. 22 and is incident on the PSDs 531 and 532.Thus, the light incident position on the PSDs also vary depending on thevertical position of reflection plate 545.

Referring to FIG. 23, assume that light reflected from the reflectionplate 545 passes through the reflected light pass hole 546 and isincident on a point P on the two-dimensional PSD 531 having an effectivelight receiving size of L (mm)×L (mm). Output currents I₁ and I₂ of thePSD 531 in the x direction are expressed by Formulae (1) and (2) shownin Example 1. Output currents I₃ and I₄ of the PSD 531 in the ydirection are expressed by Formulae (3) and (4) shown in Example 1.

For example, I₁ /I₂ and I₃ /I₄ are obtained by the above formulae asfollows:

    I.sub.1 /I.sub.2 =x.sub.1 /(L-x.sub.1)                     (19)

    I.sub.3 /I.sub.4 =y.sub.1 /(L-y.sub.1)                     (20)

By calculating the output currents of the two-dimensional PSD 531, anoutput corresponding to the position of light incident on thetwo-dimensional PSD 531 can be obtained. Likewise, from the outputcurrents I₅ and I₆, an output corresponding to the position of lightincident on the one-dimensional PSD 532, for example, I₅ /I₆ can beobtained. As a result, three outputs can be obtained from the opticalsensor 533.

As described above, the angles of light incident on the PSDs 531 and 532vary with three parameters, i.e., the tilt of the reflection plate 545in the x direction, the tilt thereof in the y direction, and thevertical position (position in the z direction) thereof. Incidentally,three output current ratios are obtained from the PSDs 531 and 532.Accordingly, the tilt of the operation section 534 in the x direction,the tilt thereof in the y direction, and the position thereof in the zdirection can be obtained uniquely. More specifically, by calculating,for example, I₁ /I₂, I₃ /I₄, and I₅ /I₆ based on the current valuesoutput from the PSDs 531 and 532, an x direction output, a y directionoutput, and a z direction output corresponding to the tilt of theoperation section 534 in the x direction, the tilt thereof in the ydirection, and the position thereof in the z direction, respectively,can be obtained. The x direction output, the y direction output, and thez direction output can also be obtained by calculating I₁ /(I₁ +I₂), I₃/(I₃ +I₄), and I₅ /(I₅ +I₆) as described in Example 1, instead of I₁/I₂, I₃ /I₄, and I₅ /I₆.

As shown in FIG. 20, the output circuit 535 of Example 5 is connected toa control circuit 560 incorporated in the computer body. In addition toa CPU, a ROM, a RAM, etc., the control circuit 560 includes theabove-described shifting section 536.

The output circuit 535 includes a signal processing circuit sections 561and 562 and an A/D conversion section 563. The signal processing circuitsections 561 and 562 calculate the values of I₁ /I₂, I₃ /I₄, and I₅ /I₆based on the output currents from the PSDs 531 and 532. The A/Dconversion section 563 converts the above analog values into digitalvalues and outputs them to the control circuit 560 as the x directionoutput, the y direction output, and the z direction output. The outputcircuit 535 which is composed of an exclusively assigned IC is mountedin the printed board 540 or in the computer body. The x directionoutput, the y direction output, and the z direction output are outputfrom three output terminals as parallel data. Alternatively, they may beoutput from a single output terminal as serial data. The x directionoutput, the y direction output, and the z direction output may also beoutput as analog values, which can be received by an A/D port of thecontrol circuit 560.

The output circuit 535 also includes an LED driving circuit section 564for driving the LED 530. The LED driving circuit section 564 controlsthe LED 530 so that the LED 530 always emits light as long as the powerswitch of the computer body is on. Alternatively, the LED 530 may beemitted intermittently like a pulse. In the latter case, the outputcurrents from the PSDs 531 and 532 may be detected in synchronizationwith the light emission of the LED 530. With this operation, theinfluence of turbulence such as noise can be eliminated, and thus thereliability can be enhanced.

The shifting section 536 calculates the shift direction and speed of thecursor according to the amounts of tilt and the movement of theoperation section 534 obtained from the three-dimensional positionalinformation, i.e., the tilt in the x direction, the tilt in the ydirection, and the position in the z direction of the operation section534, so as to shift the cursor on the screen three-dimensionally.

The cursor shift for the input device 500 with the above configurationwill be described with reference to FIGS. 18 and 20.

The stick section 550 of the operation section 534 is tilted in thedirection in which the cursor on the screen is desired to be moved. Asthe stick section 550 moves, the reflection plate 545 moves. Lightemitted from the LED 530 is reflected by the reflection plate 545, andonly the reflected light which passes through the reflected light passholes 546 and 547 is incident on the PSDs 531 and 532. The PSDs 531 and532 output currents with values corresponding to the light incidentpositions thereon. The output circuit 535 conducts calculation using theoutputs from the PSDs 531 and 532, and outputs the calculated resultscorresponding to the tilts of the operation section 534 in the x and ydirections and the vertical position thereof to the control circuit 560of the computer body as the x direction output, the y direction output,and the z direction output.

In the computer body, the shift direction and speed of the cursor arecalculated based on the received three-dimensional positionalinformation, i.e., the x, y, and z direction outputs, so as to shift thecursor on the screen under the calculated conditions. For example, whenthe operation section 534 is tilted rightward, the cursor shiftsrightward on the screen at a shift speed corresponding to the amount oftilt of the operation section 534. As the tilt of the operation section534 is large, the cursor shifts rapidly. As the tilt of the operationsection 534 is small, the cursor shifts slowly. When the operationsection 534 is tilted forward or backward, the cursor shifts downward orupward on the screen. When the operation section 534 is tilted obliquelyin a backward right direction, the cursor shifts upper rightward on thescreen. When the operation section 534 is pressed downward, the cursorshifts backward in the three-dimensional coordinate on the screen. Whenthe operation section 534 is pulled upward, the cursor shifts forward inthe three-dimensional coordinate on the screen.

Thus, the three-dimensional positional information can be obtained bythe input device employing the non-contact optical method including theoptical sensor 533 having the LED 530, the one-dimensional PSD 532, andthe two-dimensional PSD 531 and the operation section 534 which can tiltand vertically move. Based on the obtained three-dimensional positionalinformation, the cursor on the screen can be shifted in an arbitrarydirection in the three-dimensional coordinates at an arbitrary speed.

The input device of Example 5 can be modified and changed within thescope of the present invention. For example, a laser diode or afluorescent display tube may be used as the light emitting element. Twoone-dimensional PSDs disposed so that the length directions thereof areperpendicular to each other may be used instead of the two-dimensionalPSD 531. In this case, three one-dimensional PSDs are used. FIG. 24shows an example of the arrangement of three one-dimensional PSDs 532.Two of the PSDs 532 are disposed sandwiching the LED 530 so that thelength directions thereof are parallel to the direction of thearrangement of the two PSDs 532. The remaining PSD 532 is disposed sothat the length direction thereof is perpendicular to the lengthdirections of the other two PSDs 532. The input device of Example 5 maybe disposed somewhere other than the keyboard, which expands the rangeof the application of the input device.

As is apparent from the above description, the input device of Example 5uses an optical sensor combining a light emitting element, aone-dimensional PSD, and a two-dimensional PSD, or an optical sensorcombining a light emitting element, a one-dimensional PSD, and twoone-dimensional PSD disposed in directions crossing each other. Withthis configuration, the tilt and the vertical position of the operationsection when it is tilted and vertically moved can be detected so as tooutput the detected results as three-dimensional positional information.Accordingly, a cursor or an icon on the screen for a computer and thelike can be shifted three-dimensionally, i.e., rightward, leftward,upward, downward, forward, and backward. Thus, an input deviceeffectively applicable to the three-dimensional image input operationused for computer graphics and the like can be obtained.

The input device of Example 5 has a simple structure employing thenon-contact optical method and having no mechanical operation portion asin Examples 1 to 4. Malfunction due to dust entering from the outside isavoided. Accordingly, the reliability and durability of the device isimproved, and the longer life can be achieved. Further, since theoperation section and the optical sensor can be integrally formed, theinput device can be mounted on the outer surface of the computer body.Thus, since the mounting position is not limited and only a small spaceis required, the device of this example can be applied to a wider rangeof apparatuses including small-type computer related apparatuses.

(Example 6)

A sixth example of the input device according to the present inventionwill be described with reference to FIGS. 25 to 42.

Referring to FIGS. 25 to 28, an input device 600 of Example 6 integrallyincludes a movable body 620 which is displaced upon receipt of a load ina two-dimensional direction, a light emitting element 621, and a lightreceiving element 622. An image of the light emitting element 621, whichmoves in association with the displacement of the movable body 620, isformed on the light receiving element 622. The input device 600 is of aconvex shape having a T-shaped profile when viewed from above as shownin FIGS. 26A and 26B. The sizes are as shown in FIG. 27 (unit: mm). Asshown in FIGS. 29, 30A, and 30B, the input device 600 is disposed in aspace surrounded by G, H, and B keys 625 of a keyboard 624 of anapparatus 623 such as a personal computer, a wordprocessor, or the likeso that it protrudes about 1 mm above the top of the keys 625.

The movable body 620 includes a movable section 626 which is displacedby the operation of the user and a fixing section 627 for fixing themovable section 626 to the keyboard 624. The movable section 626 and thefixing section 627 are integrally formed. The light emitting element621, the light receiving element 622, and a converging lens 628 forforming the image of the light emitting element 621 on the lightreceiving element 622 are integrally formed as a reflection type tiltsensor, which is mounted on the fixing section 627 so as to face themovable section 626.

The movable section 626 is cylindrical with the top surface closed. Legs630 (e.g., FIG. 27) extend in the opposite directions along the X axisfrom the bottom rim of the cylindrical section. The T-shaped fixingsection 627 has a concave portion 631 (FIG. 25) at the bottom thereoffor receiving the tilt sensor. The legs 630 attach to the top surface ofthe X-axis portions of the fixing section 627. The Y-axis portion of thefixing section 627 includes a substrate 632 at the bottom for securingthe electrical connection with the outside circuitry. Through holes 633aand 633b are formed through the fixing section 627 and the legs 630,respectively, so as to secure the movable body 620 to the keyboard 624by screwing screws 634 through the through holes 633a and 633b.

Because the movable body 620 needs to be capable of being displaced ortilted, the movable section 626 is molded with an elastic resin, whilethe fixing section 627 is molded with a rigid resin. For the rigidresin, thermoplastic materials with a hardness of 98 or more (measuredaccording to the testing method of JIS K6301) and an elastic modulus of2000 kg/cm² or more (measured according to the testing method of ASTMD790), for example, PC (polycarbonate), ABS(acrylonitrile-butadiene-styrene), and denatured PPO (poly(phenyleneoxide)), are mainly used. For the elastic resin, thermoplastic materialswith a hardness of 70 to 98 (measured according to the testing method ofJIS K6301) and an elastic modulus of 100 to 2000 kg/cm² (measuredaccording to the testing method of ASTM D790), for example, polyesterelastomers, urethane, and rubber resins, are mainly used.

The movable section 626 and the fixing section 627 are integrally formedby two-color molding in consideration of the precision and durability.Alternatively, insert molding or fixing with screws or hooks may be usedin consideration of difficulties accompanying the molding structure andthe total cost. With the above two-layer structure having the elasticand rigid portions, the movable body 620 can be smoothly displaced whena load is applied thereto. This improves the performance of the inputdevice (pointing device).

The inner bottom surface of a top portion 635 of the movable section 626facing the tilt sensor, which has a diameter of about 5 mm, is used as areflection surface 636 for the angular detection by the tilt sensor byuse of regular reflection of light as shown in FIG. 31A. The reflectionsurface 636 is made flat and mirror-finished, galvanized, or evaporated.Alternatively, as shown in FIG. 31B, a flat plate 637 is integrallyformed on the inner bottom surface of the top portion 635 of the movablesection 626 by two-color molding or insert molding with a resin used forthe fixing section 627 or other rigid resin. The flat plate 637 may besurface-treated so as to obtain the reflection surface 636. The surfacetreatment is difficult for a soft surface made of an elastic resin, forexample. According to the alternative method, however, the surfacetreatment can be easily conducted because a rigid resin is used for theflat plate 637. Furthermore, the reflection surface 636 which isgenerally flat may be curved as shown in FIG. 31C so as to convergelight onto the light receiving element 622 effectively according to thedisplacement or tilt of the movable portion 626. Thus, by obtaining thereflection surface 636 by the surface treatment, light emitted from thelight emitting element 621 can be effectively used, so as to increasethe output of the tilt sensor and obtain sharp images. As a result, thedetection characteristic of the sensor improves.

The tilt sensor is produced in the following manner: A light emittingdiode (LED) as the light emitting element 621 and a multi-divided(quartered) photodiode as the light receiving element 622 are enclosedwith a translucent epoxy resin and the like separately, so as to formprimary molded portions 640 as shown in FIGS. 25 and 26A. Then, asecondary molded portion 641 which includes the primary molded portions640 is formed using light-shading epoxy resin or the like in such amanner that the light emitting side of the light emitting element 621and the light receiving surface of the light receiving element 622 arenot covered with the portion 641. The lens 628 is disposed above thelight emitting element 621 and the light receiving element 622, andcylindrical support legs 643 extending from the lens 628 are fitted in aring-shaped lens frame formed on the primary molded portions 640 and thesecondary molded portion 641. Thus, the tilt sensor is formed integrallyas shown in FIGS. 25 and 26B. In order to prevent an influence ofturbulence on the light receiving element 622, a visible light cuttingagent may be added to a resin material for the lens 628 before themolding of the lens 628. Quartered portions A, B, C, and D of thephotodiode as the light receiving element 622 are arranged with respectto the X axis and Y axis as shown in FIG. 32.

A pair of circular protrusions 644 are formed on the secondary moldedportion 641 as shown in FIGS. 25 and 26A. The tilt sensor is mounted onthe concave portion 631 of the fixing section 627, and the protrusions644 are fitted in through holes 645 formed in the fixing section 27 andthe movable section 626. Thus, the tilt sensor is secured in the movablebody 620 and the input device (pointing device) 600 with an integralstructure is completed. Leads 646 of the light emitting element 621 andthe light receiving element 622 are connected to the substrate 632 via aflexible printed board or the like.

Referring to FIG. 33, the input device 600 further includes a controlcircuit 652, which detects the displacement of the movable body 620based on the output of the light receiving element 622, and outputs thedetected results as information for shifting a cursor 651 or an icon ona display 650 of a computer or the like. The control circuit 652includes, in addition to a microcomputer or a control IC, an analogsignal processing circuit 653, an A/D conversion circuit 654, a digitalsignal processing circuit 655, a serial interface 656, and a drivingcircuit 657 for driving the light emitting element 621. The analogsignal processing circuit 653 conducts signal processing for outputcurrents from the light receiving element 622 and calculates X-axis andY-axis direction output signals as analog values. The A/D conversioncircuit 654 converts the analog values output from the analog signalprocessing circuit 653 into digital values. The digital signalprocessing circuit 655 converts the digital signals into signalsrepresenting shift information including the shift direction and shiftamount of the cursor. The serial interface 656 allows the controlcircuit 652 to connect with the apparatus 623 such as a computer. Theanalog signal processing circuit 653 may be formed together with thelight receiving element 622 on a same chip.

The configuration of the analog signal processing circuit 653 will bedescribed in FIG. 34. The analog signal processing circuit 653 includesa voltage conversion section 658 for converting the output currents fromthe light receiving element 622 into voltages, an addition section 659for adding the output voltages of respective sets of two of thequartered portions A, B, C, and D of the photodiode, and a subtractionsection 660 for calculating the X-axis and Y-axis direction outputs fromthe added output voltages. The voltage conversion section 658 includesone operational amplifier 661 and one resistor R1 corresponding to eachof the quartered portions A, B, C, and D of the photodiode. The additionsection 659 includes four operational amplifiers 662 and resistors R2.The subtraction section 660 includes two operational amplifiers 663 andresistors R2.

The digital signal processing circuit 655 calculates the direction andamount of the load applied to the top portion of the movable section 626by synthesizing vectors of the X-axis and Y-axis direction outputs, anddetermines the shift direction and speed of the cursor 651 based on thecalculated results. Alternatively, in place of the above operation, asimple method using software carried out by the apparatus such as thecomputer may be conducted after the A/D conversion. For example, thevectors of the X-axis and Y-axis direction outputs may be divided byrespective required division numbers. All of these divided ones arecombined to form a matrix so as to determine the two-dimensionaldirection and size.

Next, the detection principle and the input processing of the inputdevice 600 of Example 6 will be described.

As shown in FIG. 35, when the top portion 635 of the movable body 620 istilted in a two-dimensional direction with a finger, all of the movablesection 626 except for the legs 630 attached to the fixing section 627is displaced. As a result, the movable section 626 is tilted a little,so as to change the angle between the reflection surface 636 and theoptical axis of the tilt sensor. Light emitted from the light emittingelement 621 is reflected by the reflection surface 636 of the movablesection 626 after passing through the lens 628 and is then converged onthe light receiving element 622 after passing through the lens 628again. At this time, the images of the light emitting element 621 formedon the light receiving element 622 before and after the displacement ofthe movable section 626 are located at different positions.

As shown in FIG. 36, the displacement of the reflection surface 636caused by the displacement of the movable section 626 is represented bythe rotations around an axis along which the light emitting element 621and the light receiving element 622 are in line, i.e., the X axis, andthe Y axis perpendicular to the X axis. Accordingly, the direction ofthe load applied to the top portion 635 of the movable section 626 bythe user can be represented by two directions of rotations around the Xaxis and the Y axis for conducting the input processing. For example,the light image on the light receiving element 622 shifts in the Y-axisdirection by the rotation around the X axis shown in FIG. 37A. Likewise,the light image on the light receiving element 622 shifts in the X-axisdirection by the rotation around the Y axis shown in FIG. 37B. Thequartered portions A, B, C, and D of the light receiving element 622respectively output currents I_(SCA), I_(SCB), I_(SCC), and I_(SCD). Theoutput currents of the light receiving element 622 are supplied to theanalog signal processing circuit 653, and are converted into voltages bythe voltage conversion section 658 to obtain V_(A) =R1×I_(SCA), V_(B)=R1×I_(SCB), V_(C) =R1×I_(SCC), V_(D) =R1×I_(SCD). Then, since the lightimage on the light receiving element 622 shifts in the Y-axis directionfor the rotation around the X axis due to the tilt of the reflectionsurface 636, the photodiode is divided into two sets, i.e., a set of thequartered portions A and C and a set of the quartered portions B and D,and the output voltages of each set are added. Likewise, for therotation around the Y axis, the photodiode is divided into two sets,i.e., a set of the quartered portions A and B and a set of the quarteredportions C and D, and the output voltages of each set are added. As aresult, as the outputs from the addition section 659, -(V_(A) +V_(C))and -(V_(B) +V_(D))are obtained for the rotation around the X axis,while -(V_(A) +V_(B)) and -(V_(C) +V_(D)) are obtained for the rotationaround the Y axis. As the outputs from the subtraction section 660,V_(X) =(V_(A) +V_(C))-(V_(B) +V_(D)) is obtained as the vector of theX-axis direction output, while V_(Y) =(V_(A) +V_(B))-(V_(C) +V_(D)) isobtained as the vector of the Y-axis direction output.

The relationship between the rotational angle around the X axis andV_(X) is represented by a S-shaped curve having a linear portion whereV_(X) changes linearly as shown in FIG. 38. Likewise, the relationshipbetween the rotational angle around the Y axis and V_(Y) is representedby a S-shaped curve having a linear portion where V_(Y) changes linearlyas shown in FIG. 39. Accordingly, V_(X) is uniquely determined withrespect to the rotational angle around the X axis within the linearportion of V_(X), while V_(Y) is uniquely determined with respect to therotational angle around the Y axis within the linear portion of V_(Y).

Incidentally, the reason why the output currents of the sets of thequartered portions A and C and B and D are added respectively for therotation around the X axis, and the output currents of the sets of thequartered portions A and B and C and D are added respectively for therotation around the Y axis in the calculations of V_(X) and V_(Y) is toenlarge the light receiving area which can be effectively used for theshift of the light image. This addition is also effective for absorbinga variation of the light axis due to a variation of actual assembly.

Once V_(X) and V_(Y) are obtained by the analog signal processingcircuit 653, the direction and magnitude of the load applied to themovable body 620 are obtained by synthesizing the vectors in the twodirections, as shown in FIG. 40. ##EQU3## where θ is the direction and Vis the magnitude.

Thus, once V_(X) and V_(Y) are obtained, the direction θ and themagnitude V are determined. The shift direction and speed of the cursor651 are then determined based on the determined θ and V. As a result,when the movable body 620 is operated, an output corresponding to thedirection and magnitude of the operation is obtained. The cursor 651 canbe shifted on the display 650 in a desired position by a desireddistance according to this output. In other words, when a large load isapplied to the movable body 620 in a given direction, the cursor 651shifts in the direction rapidly. When a small load is applied to themovable body 620 in a given direction, the cursor 651 shifts in thedirection slowly. When the finger leaves the movable body 620, thecursor 651 stops shifting.

FIGS. 41 and 42 show the results of the optical simulation using lightray tracing method conducted to confirm that V_(X) and V_(Y) obtained bythe input device 600 of Example 6 show linear changes with respect tothe X-axis rotational angle and the Y-axis rotational angle,respectively. In this optical simulation, 120 light rays were emittedfrom the light emitting element 621 as a point light source within therange of a certain solid angle Δω. The refraction index of a resin used,the curvature of the lens 628, and the like were input into a computer,and the simulation was conducted for each light ray according to thereflection and refraction principles. The intensities of light raysfinally reaching the light receiving element 622 were then evaluated forthe 120 light rays.

In the above technique, the intensity of each of the original light raysis assumed to be 100, and total 120 light rays were emitted (totalintensity: 120×100=12000). Using the intensities of the light raysreaching the quartered photodiode as the light receiving element 622,V_(X) =(A+C)-(B+D) and V_(Y) =(A+B)-(C+D) were calculated. Thecalculated values V_(X) and V_(Y) were graphed with the rotational angleas the abscissa. These results of the simulation also show the S-shapedcurves of V_(X) and V_(Y) with respect to the rotational angle. Thus, itis confirmed that Formulae (21) and (22) for the direction θ and themagnitude V are effective by using the range where V_(X) or V_(Y) showsthe linear change as the range for the input device (pointing device)600. Incidentally, the offset in the Y-axis rotational direction in thissimulation is caused because the positional relationship between thelight emitting element 621 and the light receiving element 622 in theY-axis direction is deviated from the optimal position. The optimalposition can be obtained by repeating the simulation.

As described above, the input device (pointing device) is made small byhaving the structure of the tilt sensor and the movable body housing thetilt sensor. With this structure, the input device can be disposed in aspace surrounded by keys of the keyboard, saving the space of theapparatus such as a computer. Also, the input device of Example 6employs a non-contact optical method and includes no mechanical portion.Accordingly, high reliability and durability can be obtained. Further,since any two-dimensional displacement in all directions can be detectedin an analog fashion, the input processing can be easily conducted.Accordingly, a simple program is enough for the input processing, andthus an input device with a low total cost can be provided.

The input device 600 is not always in operation necessarily.Accordingly, the light emitting element 621 may be driven to emit lightintermittently. In this case, the output current from the lightreceiving element 622 may be detected in synchronization with the timingof the emission. This not only reduces the power consumption, but alsoeliminates an influence of turbulence such as noise, thereby enhancingthe reliability of the device.

(Example 7)

A seventh example of the input device according to the present inventionwill be described with reference to FIGS. 43 to 45B.

As shown in FIGS. 43, 44A, and 44B, an input device 700 of Example 7uses a two-dimensional PSD 770 instead of the quartered photodiode usedin Example 6. The PSD 770 is of an improved one-side division type andincludes an enclosure and a semiconductor layer enclosed therein. Thesemiconductor layer has a P-N junction for converting light, which isincident on the semiconductor layer through a window formed at the topsurface of the enclosure, into electric signals. The enclosure hasterminals for outputting the electric signals. Four electrodes 771₁,771₂, 771₃, and 771₄ are formed on the top surface as shown in FIG. 44A,and a common electrode is formed on the bottom surface. The otherstructure of the tilt sensor and the structures of other components arethe same as those of Example 6.

Light emitted from a light emitting element 621 and reflected by areflection surface of a movable body 620 is converged by a lens 628 onthe PSD 770. Light incident on the PSD 770 causes charges to begenerated at the light incident position P in proportion to the lightenergy. The charges are then output from the electrodes 771₁, 771₂,771₃, and 771₄ as currents. The light incident position can bedetermined based on the output currents from the electrodes 771₁, 771₂,771₃, and 771₄.

Referring to FIG. 45A, the relationships between the position P of thelight spot formed on the PSD 770 and the currents obtained from theelectrodes 771₁, 771₂, 771₃, and 771₄ are expressed by:

    I.sub.1 +I.sub.2 =I.sub.0 (1/2-X/L.sub.X)                  (23)

    I.sub.3 +I.sub.4 =I.sub.0 (1/2+X/L.sub.X)                  (24)

    I.sub.2 +I.sub.3 =I.sub.0 (1/2-Y/L.sub.Y)                  (25)

    I.sub.1 +I.sub.4 =I.sub.0 (1/2+Y/L.sub.Y)                  (26)

where I₀ is the total current (I₀ =I₁ +I₂ +I₃ +I₄), I₁ is the current atthe electrode 771₁, I₂ is the current at the electrode 771₂, I₃ is thecurrent at the electrode 771₃, I₄ is the current at the electrode 771₄,L_(X) is the length of the light receiving surface in the X-axisdirection, L_(Y) is the length of the light receiving surface in theY-axis direction, X is the X coordinate of the light incident positionwhen the origin of the coordinate is the center of the light receivingsurface, and Y is the Y coordinate of the light incident position whenthe origin of the coordinate is at the center of the light receivingsurface.

Then, the incident position in the X-axis direction is expressed by:

    (I.sub.1 +I.sub.2)/(I.sub.1 +I.sub.2 +I.sub.3 +I.sub.4)=1/2-X/L.sub.X (27)

or

    {(I.sub.3 +I.sub.4)-(I.sub.1 +I.sub.2)}/(I.sub.1 +I.sub.2 +I.sub.3 +I.sub.4)=2X/L.sub.X                                      (28)

The incident position in the Y-axis direction is expressed by:

    (I.sub.2 +I.sub.3)/(I.sub.1 +I.sub.2 +I.sub.3 +I.sub.4)=1/2-Y/L.sub.Y (29)

or

    {(I.sub.1 +I.sub.4)-(I.sub.2 +I.sub.3)}/(I.sub.1 +I.sub.2 +I.sub.3 +I.sub.4)=2Y/L.sub.Y                                      (30)

As described above, the vector in the X-axis and Y-axis directions canbe obtained, and the magnitude √(X² +Y²) and the direction e can beobtained as shown in FIG. 45B. Accordingly, the PSD 770 is alsoeffective for the shift control of a cursor, and thus the same functionsand effects as those of Example 6 are obtained.

(Example 8)

An eighth example of the input device according to the present inventionwill be described with reference to FIGS. 46A to 49C.

In Example 8, as shown in FIGS. 46A and 46B, four photodiodes E, F, G,and H are used as light receiving elements 822 and disposed along the Xaxis and the Y axis with respect to an LED as a light emitting element621 so as to surround the light emitting element 621. The light emittingelements 621 and the photodiodes E, F, G, and H are covered with aholder (not shown), and each has a lead terminal, and is embedded in amold of a translucent resin. The light emitting element 621 is opticallyisolated from the photodiodes E, F, G, and H so that light is notdirectly incident on the photodiodes. A lens 628 is disposed above theholder. Thus, a tilt sensor is completed.

The other components of the input device of Example 8 are the same asthose of Example 6, except for the analog signal processing circuit.Referring to FIG. 47, the analog signal processing circuit of thisexample includes a voltage conversion section 75 for converting outputcurrents from the photodiodes E, F, G, and H into voltages and asubtraction section 76 for calculating the X-axis direction output andthe Y-axis direction output by calculating the differences between thephotodiodes E and F and between the photodiodes G and H. The voltageconversion section 75 includes an operational amplifier 77 and aresistor R1 for each of the photodiodes E, F, G, and H. The subtractionsection 876 includes two operational amplifiers 78 and resistors R2.

The operation of the input device with the above configuration will nowbe described. When a top portion 635 of a movable body 620 is tilted ina two-dimensional direction with a finger, a movable section 626 of themovable body 620 is displaced. As a result, light images formed on thephotodiodes E, F, G, and H before and after the displacement of themovable section 626 are located at different positions. In other words,the displacement of a reflection surface caused by the displacement ofthe movable section 626 is represented by the rotations around an axisalong which the light emitting element 621 and the light receivingelements 822 are in line, i.e., the X axis, and the Y axis perpendicularto the X axis.

For example, the light images on the photodiodes E, F, G, and H move inthe Y-axis direction by the rotation around the X axis shown in FIG.48A. Likewise, the light images on the photodiodes E, F, G, and H movein the X-axis direction by the rotation around the Y axis shown in FIG.48B. The output currents from the photodiodes E, F, G, and H varydepending on the position of the light image. For the X-axis direction,the vector of output V_(X) =V_(E) -V_(F) is obtained from the differencebetween the voltage based on the output currents of the photodiodes Eand F. For the Y-axis direction, the vector of output V_(Y) =V_(G)-V_(H) is obtained from the difference between the voltage based on theoutput currents of the photodiodes G and H.

The relationship between the rotational angle around the X axis andV_(X) is represented by an S-shaped curve having a linear portion whereV_(X) changes linearly with respect to the rotational angle, as shown inFIG. 49A. Likewise, the relationship between the rotational angle aroundthe Y axis and V_(Y) is represented by a S-shaped curve having a linearportion where V_(Y) changes linearly with respect to the rotationalangle, as shown in FIG. 49B. Accordingly, V_(X) is uniquely determinedwith respect to the rotational angle around the X axis within the linearportion of V_(X), while V_(Y) is uniquely determined with respect to therotational angle around the Y axis within the linear portion of V_(Y).Once the outputs V_(X) and V_(Y) are obtained by the analog signalprocessing circuit, a digital signal processing circuit 655 (see FIG.33) calculates a direction θ and a magnitude V of the load applied tothe movable body 620 by synthesizing the vectors in the two directions,as shown in FIG. 49C. Thus, since the direction θ and the magnitude Vcan be obtained as described above, the shift direction and speed of acursor 651 can be determined based on the values of θ and V, so as toshift the cursor 651 on a display 650 in a desired position by a desiredlength. Accordingly, the same functions and effects as those of Example6 can be obtained.

(Example 9)

In Examples 6 to 8, the tilt sensor is composed of the light emittingelement, the light receiving element(s), and the lens. Since an LED isused as the light emitting element and light emitted by the LEDdiverges, the lens is required to converge the light. This increases thenumber of components. An input device 900 of Example 9 uses a tiltsensor with a simple structure having no lens. As shown in FIG. 50, ahologram lens 980 is formed on the bottom surface of a top portion of amovable section 626 of a movable body 620. Other structures are the sameas those of Example 6, and the same functions and effects are obtained.

The hologram lens 980 serves as both the reflection plate and the lens.Light emitted from an LED as a light emitting element 621 diverges andreaches the hologram lens 980. After being reflected by the hologramlens 980, the light is then converged toward a light receiving element622 so as to be incident on the light receiving element 622. Thus, alens can be omitted from the input device 900. Accordingly, the tiltsensor can be made smaller, and thus, the input device itself can bemade smaller.

FIG. 51 shows an input device 900a where a laser diode 981 is used asthe light emitting element in place of the LED. The laser diodeconverges light, not diverges, so that no lens is necessary. The onlyrequirement is the formation of a reflection surface 636 on the movablebody 620. Thus, the structure of the input device can be furthersimplified. The remaining structures of the input device 900a are thesame as those of Example 6, and the same functions and effects can beobtained.

(Example 10)

A tenth example of the input device according to the present inventionwill be described with reference to FIGS. 52 to 54.

In Example 10, as shown in FIG. 52, a light emitting element 621 isdisposed in a movable section 626 of a movable body 620, while a lightreceiving element 622 is disposed so as to face the light emittingelement 621. The light receiving element 622 is mounted on a substrate1086 and covered with a holder 1085 molded with a light-shading resin.The substrate 1086 is attached to the inner bottom surface of the holder1085. The holder 1085 is secured to a fixing section 627, and has acircular pinhole 1087 at the top surface thereof for allowing light topass therethrough. The light emitting element 621 is mounted on asubstrate 1088 secured to the bottom surface of a top portion 635 of themovable section 626 located above the holder 1085. Accordingly, as themovable section 626 is displaced, the light emitting element 621 isdisplaced. In Example 10, an LED is used as the light emitting element621, and a quartered photodiode is used as the light receiving element622. The structure of the movable body 620 is the same as that ofExample 6.

With the above structure, light emitted from the light emitting element621 passes through the pinhole 1087 to reach the light receiving element622. As shown in FIG. 53A, the light emitting element 621 is displacedin association with the displacement of the movable section 626, withthe same amount of displacement as that of the latter. Thus, as shown inFIG. 53B, the light image of the light emitting element 621 moves on thelight receiving element 622. At this time, the direction of thedisplacement of the movable section 626 and the direction of thedisplacement of the light image are the opposite to each other, i.e.,different by 180°. The displacement of the light image is adjustable bychanging the positional relationship among the light emitting element621, the light receiving element 622, and the pinhole 1087. Thedisplacement amount ΔL(R) of the light image on the light receivingelement 622 is expressed by:

    ΔL(R)=ΔL(E)×d.sub.1 /d.sub.2             (31)

where ΔL(E) is the displacement amount of the light emitting element621, d₁ is the distance between the top surface of the holder 1085 andthe light receiving element 622, and d₂ is the distance between the topsurface of the holder 1085 and the light emitting element 621.

Thus, the output currents of quartered portions A, B, C, and D of thephotodiode corresponding to the displacement of the movable section 626can be obtained. Thereafter, according to the signal processing methoddescribed in Example 7, the vectors of the X-axis direction output andthe Y-axis direction output are calculated, and the direction and amountof operation of the movable body 620 are calculated, so as to controlthe shift of a cursor 651. The above structure eliminates the necessityof arranging the light emitting element 621 and the light receivingelement 622 in line. In other words, since only a space for either oneof the light emitting element 621 and the light receiving element 622 isenough, the movable body 620 can be made slim, and thus the input device(pointing device) can be made smaller.

Instead of disposing the light emitting element 621 in the movablesection 626, as shown in FIG. 54, the light emitting element 621 may bedisposed in the fixing section 627 and an optical guide 1090 for guidinglight from the light emitting element 621 to the top portion 635 of themovable section 626 may be disposed in the movable section 626. Theoptical guide 1090 can be formed by embedding an optical fiber made of asynthetic resin in the movable section 626 at the time of the molding ofthe movable section 626, or by forming a portion made of a translucentresin integrally with the movable section 626 by molding. In thesealternative cases, the height, as well as the width, of the movable body620 can be made smaller. Thus, a small-size input device (pointingdevice) can be provided.

(Example 11)

An eleventh example of the input device according to the presentinvention will be described with reference to FIGS. 55 and 56.

In Example 11, a movable body 620 is not attached to a main body of anapparatus 623 such as the computer. The movable body 620 includes adome-shaped movable section 1195 and a fixing section 1196 whichelastically supports the movable section 1195 so that the movablesection 1195 can tilt upon the operation by the user. The movable body620 which has a size of a palm and a mouse-like shape is connected tothe apparatus 623 such as a computer via a connector. A tilt sensorcomposed of a light emitting element 621, a light receiving element 622,and a lens 628 formed integrally is mounted on the center of the topsurface of the fixing section 1196. The movable section 1195 is disposedto cover the tilt sensor. The movable section 1195 has a shape of aninverted cup, the bottom edge of which is inserted in a groove 1197formed at the periphery of the top surface of the fixing section 1196.An elastic material 1198 such as a spring and a rubber is placed betweenthe movable section 1195 and the fixing section 1196 so that the movablesection 1195 can be tilted. The surface of the movable section 1195facing the tilt sensor is flat and surface-finished so as to form areflection surface 1199. The structure of the tilt sensor and the inputprocessing method are the same as those described in Example 6. Theshape of the movable section is not limited to the mouse-like shape, buta polygonal shape with a size of a palm can also be used.

The movable body 620 with the above structure is thus placed on anarbitrary position. The user holds the movable section 1195 with thepalm of his or her hand in contact with the movable section 1195. Bymoving the palm forward, backward, rightward, and leftward in atwo-dimensional direction, the movable section 1195 tilts, and thus thereflection surface 1199 tilts, which makes it possible for the tiltsensor to detect the displacement of the movable section 1195. Thus,since the movable body 620 can be operated with the palm of the user'shand, the same operability as that of the mouse can be provided. In thisexample, unlike the conventional mouse, it is not necessary to move themovable body 620 on a plane. Instead, the movable body 20 can beoperated at a position where it is placed without moving. This reducesthe space required for the movable body 620, and thus makes it possibleto pursue the usability without having an influence of the conditions ofthe place where the movable body 620 is placed. Further, unlike themouse, the movable body 620 does not have a mechanical operationportion. Thus, the movable body 620 of this example is superior in thecost and reliability to the conventional pointing devices such as themouse.

The input devices of Examples 6 to 11 can be modified and changed withinthe scope of the present invention. For example, in the above examples,the movable section 626 and the fixing section 627 of the movable body620 are molded with different materials. However, it is possible to moldthe movable section 626 and the fixing section 627 with the samematerial satisfying the conditions of the hardness and the elasticmodulus both for the rigid portion and the elastic portion. This reducesthe material cost. Alternatively, the fixing section 627 may be anelastic portion, while the movable section 626 may be a rigid portion.In order to displace the movable section 620, only the portion of themovable section 626 which stands from the fixing section 627 is requiredto be elastic. Accordingly, only this portion may be made of an elasticresin. In Example 10, the positions of the light emitting element 621and the light receiving element 622 may be in reverse.

The input device (pointing device) may also be placed somewhere otherthan on the keyboard as in the above examples, and used as a substituteof a joystick or a mouse of a computer game machine or for a navigationsystem requiring switching and directional instruction. It is alsopossible to use the input device for the communications with thecomputer body via a connector as in the case of the mouse.

As is apparent from the above description, the input device of thepresent invention can be made smaller by forming the movable section andthe detector integrally. Such a small device can be placed in a spacebetween keys of the keyboard. This reduces a space required for theapparatus such as a computer. By employing the non-contact opticalmethod not requiring a mechanical operation portion, an input devicewith uniform detection precision and high reliability can be provided.Also, an input device where the input processing is easy and the totalcost is small can be realized.

Either the movable section or the fixing section is made rigid while theother section is made elastic by using the same or different materials.It is ensured, therefore, that the movable body is displaced upon a loadapplied to the movable body so as to effect the input as desired.

The surface of the movable body facing the light receiving element issurface-finished as the reflection surface. Using this reflectionsurface, light from the light emitting element can be effectively used,increasing the output of the detector and providing sharp images. Thus,the detection characteristics can be improved.

Either the light emitting element or the light receiving element may bedisposed on the movable section, while the other is disposed to face themovable section. With this structure, the area where the elements aredisposed can be reduced compared with the case where the light emittingelement and the light receiving element are arranged in line, allowingfor reducing a space required.

The movable body may have a size suitable for the operation with thepalm of the user's hand and be placed separately from the apparatus suchas the computer. This type of the input device has a good operabilitybecause the size is appropriate, and is advantageous in reducing a spacerequired for the apparatus because it is separately disposed. Further,because such an input device is not required to be moved, it can beplaced at an arbitrary place, and thus the usability can be enhanced.

Because the optical detection method is employed for detecting thedisplacement, the processing of output signals in software is easy.Thus, total cost reduction is realized.

(Example 12)

A twelfth example of the input device will be described with referenceto FIGS. 57 to 83.

An input device 1200 of Example 12 allows for three-dimensional inputoperation. Referring to FIGS. 57 to 59, the input device 1200 includes amovable body 1220, a light emitting element 1221, a light receivingelement 1222, and an optical section 1223. The movable body 1220 isdisplaced three-dimensionally by receiving a load in a three-dimensionaldirection. The light receiving element 1222 is optically coupled withthe light emitting element 1221 by the optical section 1223 and receivesa light image which shifts in association with the displacement of themovable body 1220. The optical section 1223 regulates light emitted fromthe light emitting element 1221 toward the light receiving element 1222.The input device 1200 is of a convex shape having a T-shaped profilewhen viewed from above. The sizes are as follows: the maximum length is25 mm, the maximum width is 15 mm, and the height is 10 mm. The inputdevice 1200 is disposed in a space surrounded by G, H, and B keys of akeyboard for an apparatus such as a personal computer, a wordprocessor,or the like so that it protrudes about 1 mm above the top of the keys.

The movable body 1220 is composed of a movable section 1224 which isdisplaced by the operation of the user and a fixing section 1225 forfixing the movable section 1224 to the keyboard. The movable section1224 and the fixing section 1225 are integrally formed. The lightemitting element 1221, the light receiving element 1222, and an opticalsection 1223 are integrally formed as a reflection type optical sensorS, which is mounted on the fixing section 1225 so as to face the movablesection 1224. The optical section 1223 includes a converging lens 1226and a light shader 1227 which regulates the optical path from the lightemitting element 1221 and also reflects the light so as to allow onlypart of the light to pass therethrough.

The movable section 1224 is cylindrical with the top surface closed.Legs 1228 extend in the X-axis opposite directions from the bottom rimof the cylindrical section. The T-shaped fixing section 1225 has aconcave portion 1229 at the bottom thereof for receiving the opticalsensor S. The legs 1228 of the movable section 1224 attach to the topsurface of the X-axis portions of the fixing section 1225. The Y-axisportion of the fixing section 1225 includes a substrate 1230 at thebottom thereof for securing the electrical connection with outside.Through holes 1231a and 1231b are formed through the fixing section 1225and the legs 1228 of the movable section 1224, respectively, so as tosecure the movable body 1220 to the keyboard by screwing screws 1232through the through holes 1231a and 1231b.

Because the movable body 1220 needs to be capable of being displaced inthe three-dimensional directions of the X axis, Y axis, and Z axis, themovable section 1224 is molded with an elastic material, while thefixing section 1225 is molded with a rigid material. For the rigidmaterial, thermoplastic materials with a hardness of 98 or more(measured according to the testing method of JIS K6301) and an elasticmodulus of 2000 kg/cm² or more (measured according to the testing methodof ASTM D790), for example, PC (polycarbonate), ABS(acrylonitrile-butadiene-styrene), and denatured PPO (poly(phenyleneoxide)), are mainly used. For the elastic material, thermoplasticmaterials with a hardness of 70 to 98 (measured according to the testingmethod of JIS K6301) and an elastic modulus of 100 to 2000 kg/cm²(measured according to the testing method of ASTM D790), for example,polyester elastomers, urethane, and rubber resins, are mainly used.

The movable section 1224 and the fixing section 1225 are integrallyformed by two-color molding in consideration of the precision anddurability. Alternatively, insert molding or fixing with screws or hooksmay be used in consideration of difficulties accompanying the moldingstructure and the total cost. With the above two-layer structure havingthe elastic and rigid portions, the movable body 1220 can be smoothlydisplaced when a load is applied thereto in the X-axis and Y-axisdirections two-dimensionally and in the Z-axis directionthree-dimensionally. This improves the performance of the pointingdevice allowing for the three-dimensional input. The two-dimensionaldisplacement is represented by the rotations, or tilt, around the X axisand Y axis by Δθ as shown in FIG. 60B. The three-dimensionaldisplacement is represented by the lowering in the Z-axis direction byΔh as shown in FIG. 60C.

The inner bottom surface of a top portion 1233 of the movable section1224 facing the optical sensor S, which has a diameter of about 5 mm, isused as a reflection surface 1234 for the angular detection by theoptical sensor S by use of regular reflection of light. The reflectionsurface 1234 is made flat and mirror-finished, galvanized, orevaporated. Accordingly, the angle of the reflection surface 1234changes for the two-dimensional displacement, while the distance betweenthe reflection surface 1234 and the optical sensor S changes for thedisplacement in the Z-axis direction.

An alternative example of the reflection surface 1234 is shown in FIG.61. A flat plate 1235 is formed on the inner bottom surface of the topportion 1233 of the movable section 1224 by two-color molding or insertmolding with a resin used for the fixing section 1225 or other rigidresin. The flat plate 1235 is surface-treated so as to obtain thereflection surface 1234. The surface treatment is difficult for a softsurface such as an elastic resin. According to the alternative method,however, the surface treatment can be easily conducted to obtain a highflatness because a rigid resin is used for the flat plate 1235. The flatplate even reinforces the movable section 1224. Furthermore, thereflection surface 1234 which is generally flat may be curved so as toconverge light onto the light receiving element 1222 effectivelyaccording to the displacement or tilt of the movable portion 1224. Thus,by obtaining the reflection surface 1234 by the surface treatment, lightemitted from the light emitting element 1221 can be effectively used,thereby to increase the output of the optical sensor S and to obtainsharp images. As a result, the detection characteristic of the sensorimproves.

The structure of the movable body 1220 is not limited to that describedabove, but any structures where part of the movable body 1220 is elasticas shown in FIGS. 62A to 62E and 63A to 63D are acceptable as themovable body 1220. In FIGS. 62A to 62E and 63A to 63D, elastic portions1236 are shown by right-downward oblique lines, while rigid portions1237 are shown by left-downward oblique lines. In FIG. 62A, the portionof the fixing section 1225 coupling with the movable section 1224constitutes the elastic portion 1236, while the remaining of the fixingsection 1225 and the movable section 1224 constitute the rigid portion1237. In this case, the entire movable section 1224 is displacedthree-dimensionally. In FIG. 62B, the movable section 1224 constitutesthe rigid portion 1237, while the fixing section 1225 constitutes theelastic portion 1236. In this case, the entire movable section 1224 isdisplaced three-dimensionally with a large tilt. In FIG. 62C, part ofthe upper portion of the movable section 1224 constitutes the elasticportion 1236, while the remaining of the movable section 1224 and thefixing section 1225 constitute the rigid portion 1237. In this case,only the upper portion of the movable section 1224 is displaced by asmall amount. In FIG. 62D, part of the lower portion of the movablesection 1224 constitutes the elastic portion 1236, while the remainingof the movable section 1224 and the fixing section 1225 constitute therigid portion 1237. In this case, the upper portion of the movablesection 1224 is displaced with a smaller tilt. In FIG. 62E, the upperhalf of the movable section 1224 constitutes the elastic section 1236,while the remaining of the movable section 1224 and the fixing section1225 constitute the rigid portion 1237. In this case, only the upperhalf of the movable section 1224 is displaced with a smaller tilt.

In FIG. 63A, the inner circumference of the movable section 1224constitutes the rigid portion 1237 except for a portion thereof whichconstitutes the elastic portion 1236 together with the remaining of themovable section 1224. The fixing section 1225 constitutes the rigidportion 1237. In this case, the movable section 1224 is displaced with asmaller tilt. In FIG. 63B, the inner portion of the movable section 1224constitutes the rigid portion 1237 except for the bottom portionthereof, which constitutes the elastic portion 1236 together with theremaining of the movable section 1224. The fixing section 1225constitutes the rigid portion 1237. In this case, the entire movablesection 1224 is displaced with a small amount. In FIG. 63C, the innerportion of the movable section 1224 and the bottom ends of the fixingsection 1225 constitute the rigid portion 1237, while the remaining ofthe movable section 1224 and the remaining of the fixing section 1225integrally constitute the elastic portion 1236. Protrusions 1238 forpreventing the falling of the movable section 1224 are formed on thebottom of the fixing section 1225. In this case, the entire movablesection 1224 is displaced with a large tilt, though the displacement inthe Z-axis direction is small because the protrusions 1238 regulate thedisplacement. In FIG. 63D, the inner portion of the movable section 1224constitutes the rigid portion 1237, while the remaining of the movablesection 1224 and the fixing section 1225 integrally constitute theelastic portion 1236. The coupling portion of the fixing section 1225with the movable section 1224 is thinned. In this case, the entiremoving section 1224 is displaced with a smaller tilt, though thedisplacement in the Z-axis direction is large. Thus, the movable bodiesshown in FIGS. 63A to 63D not only have an elastic structure, but alsohave a function of a limiter of the displacement (tilt).

The elastic structure can be provided not only by the selection ofmaterials of the movable section 1224 and the fixing section 1225, butalso by the selection of the shape thereof. For example, as shown inFIG. 64, the movable section 1224 can be displaced largely by formingcuts 1239 around the outer circumference thereof. FIGS. 65A to 65D showexamples of sections of the elastic portion 1236 to be formed as aportion of the movable section 1224. FIGS. 65A to 65D show a rectangularshape, an inverted U shape, an inverted U shape having a protrusion atthe center, and an inverted E shape, respectively. Further, as shown inFIG. 66, the movable section 1224 may be divided into two portionsvertically, and springs 1240 may be disposed therebetween.

The optical sensor S is produced in the following manner: A lightemitting diode (LED) as the light emitting element 1221 and amulti-divided (quartered) photodiode as the light receiving element 1222are enclosed with a translucent epoxy resin and the like separately, soas to form primary molded portions 1241. Then, a secondary moldedportion 1242 which includes the primary molded portions 1241 is formedusing a light-shading epoxy resin and the like. As shown in FIG. 57, thelens 1226 is disposed above the light emitting element 1221 and thelight receiving element 1222, and cylindrical support legs 1244extending from the lens 1226 are movably fitted in a ring-shaped lensframe 1243 formed on the primary molded portions 1241 and the secondarymolded portion 1242. Thus, the optical sensor is formed integrally.Quartered portions A, B, C, and D of the photodiode as the lightreceiving element 1222 are arranged with respect to the X axis and Yaxis as shown in FIG. 67.

The light shader 1227 (FIGS. 68A and 68B) is obtained by forming a thinfilm of a light shading material on the bottom surface of the lens 1226facing the light emitting element 1221 and the light receiving element1222 by sputtering, evaporation, attachment, or the like, or by formingintegrally with the lens 1226 of a light shading resin. As shown inFIGS. 68A and 68B, the light shader 1227 has a circular light emittingwindow 1245 formed at a position located above the light emittingelement 1221 for allowing light from the light emitting element 1221 topass therethrough, and a square light receiving window 1246 formed at aposition located above the light receiving element 1222 for allowinglight reflected toward the light receiving element 1222 to passtherethrough. These windows are formed along the X axis to besymmetrical with respect to the center axis of the lens 1226. The lightshader 1227 may be disposed on the top surface of the lens 1226, oranywhere between the lens 1226 and the combination of the light emittingelement 1221 and the light receiving element 1222. The light shader 1227is used for the light receiving element 1222 in order to allow onlylight reflected from the movable section 1224 to be incident on thelight receiving element 1222. Thus, the light shader 1227 can be formedonly above the light receiving element 1222 and may not necessarily beformed above the light emitting element 1221.

As shown in FIGS. 57 and 58B, a pair of circular protrusions 1247 areformed on the secondary molded portion 1242. The optical sensor S ismounted on the concave portion 1229 of the fixing section 1225, and theprotrusions 1247 are fitted in through holes 1248 formed in the fixingsection 1225 and the movable section 1224. In this way, the opticalsensor S is secured in the movable body 1220 so as to complete the inputdevice (pointing device) with an integral structure. Leads 1249 of thelight emitting element 1221 and the light receiving element 1222 areconnected to the substrate 1230 via a flexible printed board and thelike.

The input device of this example is provided with a control circuit 1263as shown in FIG. 69, which detects a displacement of the movable body1220 operated by the user through the outputs of the light receivingelement 1222 and outputs the detected results as information forshifting a cursor 1262 or an icon on a display 1261 of an apparatus 1260such as a computer. The control circuit 1263 includes a microcomputer ora control IC. The optical sensor S includes an integrally-formed analogsignal processing circuit 1264, which conducts signal processing of theoutput currents from the light receiving element 1222 so as to calculatethe X-axis, Y-axis, and Z-axis direction outputs. The control circuit1263 includes an A/D conversion section 1265, a digital signalprocessing section 1266, a serial interface 1267, and a driving circuitsection 1268 for driving the light emitting element 1221. The A/Dconversion section 1265 converts the analog values of the X-axis,Y-axis, and Z-axis direction outputs from the analog signal processingcircuit 1264 into digital values. The digital signal processing section1266 converts the digital signals into signals representing shiftinformation including the shift direction and amount of the cursor. Theserial interface 1267 allows the connection with the apparatus 1260 suchas a computer.

A configuration of the analog signal processing circuit 1264 is shown inFIG. 70. The analog signal processing circuit 1264 includes a voltageconversion section 1269 for converting the output currents from thelight receiving element 1222 into voltages, an addition section 1270 foradding the output voltages of given two of the quartered portions A, B,C, and D of the photodiode, and a subtraction section 1271 forcalculating the X-axis, Y-axis, and Z-axis direction outputs from theadded output voltages. The voltage conversion section 1269 includes anoperational amplifier 1272 and a resistor R1 for each of the quarteredportions A, B, C, and D of the photodiode. The addition section 1270includes four operational amplifiers 1273 and resistors R2. Thesubtraction section 1271 includes three operational amplifiers 1274 andresistors R2.

The digital signal processing section 1266 calculates the direction andamount of a load by synthesizing vectors of the three direction outputs,and determines the direction, speed, acceleration of the shift of thecursor 1262 based on the calculated results. Alternatively, in place ofthe above operation, a simple method using a software processing on theside of the apparatus such as a computer may be conducted after the A/Dconversion. For example, the vectors of the three direction outputs maybe divided by respective required division numbers. All of these dividedones are combined to form a matrix so as to determine thethree-dimensional direction and size.

Next, the detection principle and the input processing of the inputdevice (pointing device) of Example 12 will be described.

First, for the two-dimensional input, the distance between thereflection surface 1234 of the movable section 1224 and the bottomsurface of the optical sensor S is H, as shown in FIG. 68A. Thereflection surface 1234 is not tilted when the movable body 1220 is notoperated. Light emitted from the light emitting element 1221 passesthrough the light emitting window 1245 of the light shader 1227 and isreflected by the reflection surface 1234 via the lens 1226. Then, thereflected light passes through the light receiving window 1246 of thelight shader 1227 via the lens 1226, so as to form an image at thecenter of the light receiving element 1222. When the top portion 1233 ofthe movable section 1224 is operated in a two-dimensional direction witha finger, all of the movable section 1224 except for the legs 1228attached to the fixing section 1225 is displaced. As a result, themovable section 1224 is tilted a little, so as to change the anglebetween the reflection surface 1234 and the optical axis of the opticalsensor S. Light emitted from the light emitting element 1221 isreflected by the reflection surface 1234 of the movable section 1224after passing through the light emitting window 1245 and the lens 1226and is then converged on the light receiving element 1222 after passingthrough the lens 1226 again and the light receiving window 1246. At thistime, light images formed on the light receiving element 1222 before andafter the displacement of the movable section 1224 are located atdifferent positions.

At this time, as shown in FIG. 71, the displacement of the reflectionsurface 1234 caused by the displacement of the movable section 1224 isrepresented by the rotations around an axis along which the lightemitting element 1221 and the light receiving element 1222 are in line,i.e., the X axis, and the Y axis perpendicular to the X axis.Accordingly, the direction of the load applied to the top portion 1233of the movable section 1224 by the user can be represented by twodirections of rotations around the X axis and the Y axis so as to detecta change of the angle of the reflection surface 1234 for conducting theinput processing. For example, the light image formed on the lightreceiving element 1222 shifts in the Y-axis direction as shown in FIG.72B, when the reflection surface 1234 is rotated around the X axis asshown in FIG. 72A. Likewise, the light image on the light receivingelement 1222 shifts in the X-axis direction as shown in FIG. 73B, whenthe reflection surface 1234 is rotated around the Y axis shown in FIG.73A.

The quartered portions A, B, C, and D of the light receiving element1222 respectively output currents I_(SCA), I_(SCB), I_(SCC), andI_(SCD). The output currents of the element 1222 are supplied to theanalog signal processing section 1264 shown in FIG. 69, and areconverted into voltages by the voltage conversion section 1269 to obtainV_(A) =R1×I_(SCA), V_(B) =R1×I_(SCB), V_(C) =R1×I_(SCC), V_(D)=R1×I_(SCD) as shown in FIG. 70. Then, since the light image on thelight receiving element 1222 shifts in the Y-axis direction for therotation around the X axis due to the tilt of the reflection surface1234, the element 1222 is divided into two sets, i.e., a set of thequartered portions A and C and a set of the quartered portions B and D,and the output voltages of each set are added. Likewise, for therotation around the Y axis, the photodiode is divided into two sets,i.e., a set of the quartered portions A and B and a set of the quarteredportions C and D, and the output voltages of each set are added. As aresult, as the output from the addition section 1270, -(V_(A) +V_(C))and -(V_(B) +V_(D)) are obtained for the rotation around the X axis,while -(V_(A) +V_(B)) and -(V_(C) +V_(D)) are obtained for the rotationaround the Y axis. As the output from the subtraction section 1271,V_(X) =(V_(A) +V_(C))-(V_(B) +V_(D)) is obtained as the X-axis directionoutput, while V_(Y) =(V_(A) +V_(B))-(V_(C) +V_(D)) is obtained as theY-axis direction output.

The relationship between the rotational angle around the X axis andV_(X) is represented by a S-shaped curve having a linear portion whereV_(X) changes linearly as shown in FIG. 74. Likewise, the relationshipbetween the rotational angle around the Y axis and V_(Y) is representedby a S-shaped curve having a linear portion where V_(Y) changes linearlyas shown in FIG. 75. Accordingly, V_(X) is uniquely determined withrespect to the rotational angle around the X axis within the linearportion of V_(X), while V_(Y) is uniquely determined with respect to therotational angle around the Y axis within the linear portion of V_(Y).Incidentally, the output currents of the quartered portions A and C andB and D are added respectively for the rotation around the X axis, andthe output currents of the quartered portions A and B and C and D areadded respectively for the rotation around the Y axis in order toenlarge the light receiving area which can be effectively used for theshift of the light image. This addition is also effective for absorbinga variation of the light axis due to a variation of actual assembly.

Once V_(X) and V_(Y) are obtained by the analog signal processingsection 1264, the direction and magnitude of the load applied to themovable body 1220 are obtained by synthesizing the vectors in the twodirections, as shown in FIG. 76. ##EQU4## where θ is the direction and Vis the magnitude.

Thus, once V_(X) and V_(Y) are obtained, the direction θ and themagnitude V are determined. The shift direction, speed, acceleration,etc. of the cursor 1261 are then determined based on the determined θand V.

Next, the displacement in the Z-axis direction will be described withreference to FIG. 77.

The movable section 1224 is pressed downward and displaced in the Z-axisdirection. Light emitted from the light emitting element 1221 passesthrough the light emitting window 1245 and the lens 1226 and reflectedby the reflection surface 1234. The reflected light passes through thelens 1226 again to reach the light shader 1227. While most of the lightpasses through the light receiving window 1246 to reach the lightreceiving element 1222, part of the light is prevented from passingthrough the light receiving window 1246 and does not reach the lightreceiving element 1222. Accordingly, the light amount received by thelight receiving element 1222 becomes smaller than that received beforethe displacement of the movable section 1224 in the Z-axis direction.The analog signal processing section 1264 calculates V_(Z) =V_(A) +V_(B)+V_(C) +V_(D) based on the light amount received by the light receivingelement 1222 as the Z-axis direction output. When the movable section1224 is displaced by ΔH, all of the light from the light emittingelement 1221 is shaded by the light shader 1227, not reaching the lightreceiving element 1222. Thus, the displacement in the X-axis directioncan be obtained by comparing the absolute value of the outputs V_(Z)before and after the displacement in the Z-axis direction.

The analog signals for a three-dimensional direction obtained by theabove processing are input in the control circuit 1263 as shown in FIG.69. In the control circuit 1263, the A/D conversion section 1265converts the analog signals into digital signals with a requiredresolution. The 4-bit or 8-bit resolution is appropriate. The convertedsignals are then converted into serial signals in the X-axis, Y-axis,and Z-axis directions by the digital signal processing circuit section1266 and sent to the serial interface 1267. The serial interface 1267conducts input/output operation with a mouse interface of the apparatus1260 such as a computer.

As a result, by operating the movable body 1220 in a two-dimensionaldirection, outputs corresponding to the direction and magnitude of theoperation is obtained. The cursor 1262 can be shifted on the display1261 to a desired position by a desired distance according to thisoutput. When a large load is applied to the movable body 1220 in a givendirection, the cursor 1262 shifts in the direction rapidly. When a smallload is applied to the movable body 1220 in a given direction, thecursor 1262 shifts in the direction slowly. When the finger leaves themovable body 1220, the cursor 1262 stops shifting. Further, by operatingthe movable body 1220 in the Z-axis direction, a shift in athree-dimensional direction on the display 1261 corresponding to theamount of operation is obtained. The cursor 1262 can thus be shifted onthe display 1261 three-dimensionally.

The operation of the movable body 1220 in the Z-axis direction can alsoprovide a click function. Clicking or dragging can be input by theoperation of the movable body 1220 by providing a click circuit. In sucha click circuit, the output of the optical sensor S is subjected tolevel-slicing depending on whether or not the output exceeds a certainthreshold. Thus, the click circuit outputs an ON signal when the outputexceeds the threshold, while it outputs an OFF signal when the outputdoes not exceed the threshold. In this case, the input device has atwo-dimensional input function, not the three-dimensional inputfunction.

In order to implement both the three-dimensional input function and theclick function, a temporal element should be added at the detection ofthe operation of the movable body 1224. More specifically, the timeduration of the output of the optical sensor S obtained by the operationin the Z-axis direction is measured. The operation is judged as theclick when the output time duration is shorter than a predeterminedvalue, while it is judged as the three-dimensional input when it islonger than the predetermined value. Based on this judgement, either ofthe above operations is conducted.

FIGS. 78A and 78B show the results of the optical simulation using lightray tracing method conducted to confirm that V_(X) and V_(Y) obtained bythe input device (pointing device) of Example 12 show linear changeswith respect to the X-axis rotational angle and the Y-axis rotationalangle. In this optical simulation, 120 light rays were emitted from thelight emitting element 1221 as a point light source within the range ofa certain solid angle Δω. The refraction index of a resin used, thecurvature of the lens 1226, and the like were input into a computer, andthe simulation was conducted for each light ray according to thereflection and refraction principles. The intensities of light raysfinally reaching the light receiving element 1222 were then evaluatedfor the 120 light rays.

In the above technique, the intensity of each of the original light raysis assumed to be 100, and total 120 light rays were emitted (totalintensity: 120×100=12000). Using the intensities of the light raysreaching the quartered photodiode as the light receiving element 1222,V_(X) =(A+C)-(B+D) and V_(Y) =(A+B)-(C+D) were calculated. Thecalculated values V_(X) and V_(A) were graphed with the rotational angleas the abscissa. These results of the simulation also show the S-shapedcurves of V_(X) and V_(Y) with respect to the rotational angle. Thus, itis confirmed that Formulae (32) and (33) for the direction θ and themagnitude V are effective by using the range where V_(X) or V_(Y) showsthe linear change as the range for the input device (pointing device).Incidentally, the offset in the Y-axis rotational direction in thissimulation is caused because the positional relationship between thelight emitting element 1221 and the light receiving element 1222 in theY-axis direction is deviated from the optimal position. The optimalposition can be obtained by repeating the simulation.

As the simulation of the displacement in the Z-axis direction, it wasobserved that, by setting the conditions of the above describedparameters, light did not reach the light receiving element 1222 whenthe reflection surface 1234 was lowered by ΔH (=1.5 mm, when the maximumdistance between the lens 1226 and the reflection surface 1234 is 2.4mm) as shown in FIG. 79. It was also observed that, when the reflectionsurface 1234 in the tilted state was displaced by ΔH in the Z-axisdirection, light did not reach the light receiving element 1222, either,depending on the value of ΔH. The value of ΔH with respect to thedistance H between the reflection surface 1234 and the optical sensor S,as well as the sizes of the windows 1245 and 1246 and the positionalrelationship therebetween, should be designed in consideration ofparameters such as the positional relationship between the lightemitting element 1221 and the light receiving element 1222, the focaldistance of the lens 1226, and the like.

As described above, one input device can provide a plurality of inputfunctions by having the structure of the optical sensor S and themovable body 1220 housing the optical sensor S and movablethree-dimensionally. With this structure, the number of components canbe reduced and thus the size of the device can be reduced. Such a smallinput device can be disposed in a space surrounded by keys of thekeyboard, saving the space of the apparatus such as a computer. Also,the input device of Example 12 employs a non-contact optical methodwhich does not include any mechanical portion. Accordingly, highreliability and durability can be obtained. Further, since anythree-dimensional displacement in all directions can be detected in ananalog fashion, the input processing can be easily conducted.Accordingly, a simple program is enough for the input processing, andthus an input device (pointing device) with a low total cost can beprovided.

The input device is not always under operation. Accordingly, it is notnecessary for the light emitting element 1221 to always emit light whenthe apparatus 1260 such as a computer is on. Instead, the light emittingelement 1221 may be driven to emit light intermittently. In this case,the output current from the light receiving element 1222 may be detectedin synchronization with the timing of the emission. This not onlyreduces the power consumption, but also eliminates an influence ofturbulence such as noise, thereby enhancing the reliability of thedevice.

In Example 12, the click circuit was described where ON/OFF signals wereobtained by level-slicing the output of the optical sensor S indicatingthe displacement of the movable body 1220 in the Z-axis direction. Insuch a click circuit, however, a clicking touch is not obtained when themovable body 1220 is pressed by the user. This does not providesatisfaction in the aspect of human engineering. Modifications ofExample 12 for providing the clicking touch for the displacement in theZ-axis direction will be described as follows.

Referring to FIG. 80, in a modified input device, the movable section1224 constituting the elastic portion. The movable section 1224 includesa top portion 1233 where the reflection surface is formed, a lowerportion which is seated on the fixing section 1225, and a couplingportion 1280 having a thin thickness (0.4 mm) and a given angle (30° to40°) between the top portion 1233 and the lower portion. The remainingstructures are the same as those of Example 12. Alternatively, themovable body may have a structure as shown in FIG. 81, where, themovable section 1224 constitutes the elastic portion and includes thetop portion 1233, the lower portion, and a coupling portion 1280 havinga thin thickness (0.4 mm) and a given angle (30° to 40°) between the topportion 1233 and the lower portion. In this case, the top portion 1233is covered with a rigid operation portion 1281 with a large diameter. Inthe latter case, the top portion 1233 must be thickened to have astrength large enough to support the operation portion 1281. This makesthe distance between the optical sensor S and the reflection surface1234 shorter than the minimum distance. In order to solve this problem,a concave area is formed at the center of the bottom of the top portion1233. With these structures of the modified examples, when the movablesection 1224 is pressed to some extent, the coupling portion 1280abruptly deforms and collapses, thus providing the clicking touch.Accordingly, the user can feel that the click function has beenexecuted. This improves the operability of the device.

Other modifications of Example 12 are shown in FIGS. 82A, 82B, and 83.In these modified examples, protrusions 1282 extend from the bottomsurface of the top portion 1233 of the movable body 1220 shown in FIGS.80 or 81. A conductor 1283 is disposed on each of the bottom end of theprotrusions 1282. A conductive pattern 1284 is formed on the surface ofthe substrate 1230 facing the protrusions 1282 as shown in FIG. 82B.When the movable section 1224 is displaced in the Z-axis direction, theprotrusions 1282 lowers, so that the conductors 1283 contact theconductive pattern 1284, allowing to provide a switch function. Thisstructure can be used to provide the input device with the clickfunction and the drag function. The structure as shown in FIGS. 82A,82B, and 83 may also be used as a switch function itself additionallyprovided to the input device (pointing device). In this case, an inputdevice having multi-functions can be realized.

Further, in the above modified examples having the protrusions toprovide the click function, the cursor and the like can be shiftedthree-dimensionally by inputting into the computer signals correspondingto the direction and amount of the operation based on the absolute ofthe output V_(Z) of the optical sensor S obtained by the displacement ofthe movable body 1220 in the Z-axis direction. Thus, a pointing devicehaving both the three-dimensional input function and the click functioncan be realized.

(Example 13)

A thirteenth example of the input device according to the presentinvention will be described with reference to FIGS. 84 to 90B.

As shown in FIG. 84, a light emitting element 1221 is disposed on amovable section 1224 which can be moved vertically. A light receivingelement 1222 is formed to face the light emitting element 1221. Morespecifically, the light emitting element 1221 is disposed on a substrate1390 secured to a top portion 1233 of the movable section 1224. Thelight receiving element 1222 is covered with a holder 1391 made of alight-shading resin and is mounted on a substrate 1392 secured to thebottom of the holder 1391. The holder 1391 is secured to a fixingsection 1225. A circular pinhole 1393 for restricting light incident onthe light receiving element 1222 is formed at the top portion of theholder 1391 which is located somewhere in the optical axis between thelight emitting element 1221 and the light receiving element 1222. Thus,a transmissive type optical sensor is formed. An LED is used as thelight emitting element 1221, and a quartered photodiode is used as thelight receiving element 1222. The structure of the movable body 1220 isthe same as that of Example 12.

With the above structure, when the user does not operate the movablebody 1220, light emitted from the light emitting element 1221 reachesthe light receiving element 1222 via the pinhole 1393, as shown in FIG.85A. In this case, however, the light image formed on the lightreceiving element 1222 is small and the total light amount received bythe light receiving element 1222 is small. This is because only thelight in the range of a solid angle Δω reaches the light receivingelement 1222.

When the movable body 1220 is operated in a two-dimensional direction bya finger as shown in FIG. 86A, the light emitting element 1221 moves inassociation with the displacement of the movable section 1224.Accordingly, the light image formed on the light receiving element 1222shifts in a direction opposite to the direction of the displacement ofthe movable section 1224 while the size of the light image remainsunchanged. The detection of the output from the light receiving element1222 is the same as that described in Example 12. In this case, however,the output change with respect to the angle is replaced with the outputchange with respect to the displacement.

Then, as shown in FIG. 87A, when the movable section 1224 is pressed anddisplaced in the Z-axis direction, the distance between the lightemitting element 1221 and the pinhole 1393 becomes short. At this time,the light in the range of a solid angle Δω' (>Δω) reaches the lightreceiving element 1222. Accordingly, the light image on the lightreceiving element 1222 is larger and the total light amount received bythe light receiving element 1222 is larger than the case where themovable section 1224 is not displaced in the Z-axis direction. FIG. 89Bshows the variation in the total light amount received by the lightreceiving element 1222 as a function of the displacement of the movablesection 1224 in the Z-axis direction. The relationship between thedistance between the light emitting element 1221 and the pinhole 1393and the relative received light amount is expressed by:

    I'=I×(d/d').sup.2                                    (34)

where d and d' denote the distance between the light emitting element1221 and the pinhole 1393 before and after the displacement,respectively, and I and I' denote the relative received light amountbefore and after the displacement, respectively.

Then, when the movable section 1224 is operated in a two-dimensionaldirection while being pressed in the Z-axis direction, the movablesection 1224 is displaced three-dimensionally, as shown in FIG. 88A. Atthis time, the light image shows the shift obtained by synthesizing theabove-described displacements in the directions, and therefore the shiftof the light image on the light receiving element 1222 corresponding tothe displacement in the two-dimensional direction is large, as shown inFIG. 88B. The displacement ΔL' of the light image on the light receivingelement 1222 is expressed by:

    ΔL'=ΔL×D/d'                              (35)

where ΔL denotes the displacement of the light emitting element 1221, Ddenotes the distance between the pinhole 1393 and the light receivingelement 1222 (constant), and d' denotes the distance between the pinhole1393 and the light emitting element 1221.

When a load is applied in the Z-axis direction, as well as in atwo-dimensional direction, d' is smaller compared with the case where noload is applied in the Z-axis direction. Thus, the ΔL' is larger when ΔLis unchanged. In other words, as shown in FIG. 90A, the unit changeamount in the S-shaped curve of the outputs V_(X) and V_(Y) in theX-axis and Y-axis directions with respect to the displacement ΔL when aload is applied in the Z-axis direction differs from that when no loadis applied in the Z-axis direction. Referring to FIG. 90A, when a loadis applied in the Z-axis direction, the sensitivity is higher by b/athan in the case where no load is applied. This changes the outputs inthe X-axis and Y-axis directions depending on whether or not a load isapplied in the Z-axis direction, and thus lowers the operability. Inorder to solve this problem, the values V_(X) and V_(Y) are multipliedby a correction coefficient obtained based on Formula (34), so as tostabilize the changes of the outputs V_(X) and V_(Y) in the X-axis andY-axis directions within the linear range of the S-shaped curve withrespect to the displacement ΔL irrelevant of the displacement in theZ-axis direction, as shown in FIG. 90B. Thus, an appropriate operabilitycan be obtained.

For example, when the distance d' between the pinhole 1393 and the lightemitting element 1221 is reduced to a half, the total received lightamount of the light receiving element 1222 becomes quadruple. At thistime, the sensitivity to the displacement ΔL of the outputs V_(X) andV_(Y) in the X-axis and Y-axis directions also becomes quadruple. Thechange of the distance d' is detected by monitoring the total lightamount received by the light receiving element 1222, and the outputsV_(X) and V_(Y) are multiplied by a correction coefficient when a changeis detected. In this case, the outputs V_(X) and V_(Y) are multiplied by1/4, so as to obtain the equal sensitivity to the displacement ΔL of theoutputs V_(X) and V_(Y) obtained when no load is applied in the Z-axisdirection.

Once the outputs of the optical sensor S corresponding to thedisplacements in the three-axial directions are obtained as describedabove, the X-axis, Y-axis, and Z-axis direction outputs are obtained inaccordance with the signal processing technique described in Example 12,so as to calculate the direction and amount of the load applied to themovable body 1220. Thus, the three-dimensional shift of the cursor 1262is controlled. The above structure eliminates the necessity of arrangingthe light emitting element 1221 and the light receiving element 1222 inline. In other words, since only a space for either one of the elements1221 and 1222 is enough, the movable body 1220 can be made slim, andthus the input device (pointing device) can be made smaller.

Also, as described in Example 12, a temporal element may be added to theoperation in the Z-axis direction, so as to provide the input devicewith the click function. Alternatively, instead of the three-dimensionalinput function, the two-dimensional input function and the clickfunction may be combined.

In Example 13, instead of disposing the light emitting element 1221 inthe movable section 1224, the light emitting element 1221 may bedisposed in the fixing section 1225 and an optical guide for guidinglight from the light emitting element 1221 to the top portion 1233 ofthe movable section 1224 may be disposed in the movable section 1224. Inthis alternative case, the height, as well as the width, of the movablebody 1220 can be made smaller. Thus, a small-size input device can beprovided. Alternatively, the light receiving element 1222 may bedisposed on the movable section 1224, while the light emitting element1221 may be disposed on the fixing section 1225.

The input devices of Examples 12 and 13 can be modified and changedwithin the scope of the present invention. For example, in the aboveexamples, the movable section and the fixing section of the movable bodyare molded with different materials. However, it is possible to mold themovable section and the fixing section with the same material satisfyingthe conditions of the hardness and the elastic modulus both for therigid portion and the elastic portion. This reduces the material cost.

A two-dimensional PSD may be used as the light receiving element inplace of the quartered photodiode. When light reflected by thereflection surface of the movable body reaches the PSD, electric chargesare generated at the light incident position in proportion to the lightenergy. The charges are output as currents. Based on the currents, thelight incident position on the PSD can be determined, so as to obtainthe outputs in the X-axis and Y-axis directions. The output in theZ-axis direction is also obtained from the total output current, andthus the three-dimensional input is possible. Alternatively, fourphotodiodes may be disposed along the X-axis and Y-axis with respect toan LED as the light emitting element so as to surround the LED.

The input device (pointing device) may also be placed somewhere otherthan on the keyboard as in the above examples, and used as a substituteof a joystick or a mouse of a computer game machine or for a navigationsystem requiring switching and directional instruction. It is alsopossible to use the input device for the communications with thecomputer body via a connector as in the case of the mouse.

As is apparent from the above description, the input device of thepresent invention integrally includes the movable body capable ofdisplacing three-dimensionally upon receipt of a load in athree-dimensional direction and the optical section regulating lightemitted from the light emitting element toward the light receivingelement, so as to be provided with the three-dimensional input functionand the click function. With this structure, it is possible to achieve amulti-functional output device having many functions. This makes itpossible to obtain a small-size apparatus such as a computer with areduced space required.

Since the detection of the displacement of the movable body is performedby the non-contact optical method, no mechanical operation portion isinvolved. Thus, an input device with uniform detection precision andhigh reliability can be provided. Also, an input device where the inputprocessing of the outputs from the light receiving element is easy andthe total cost is small can be realized.

Either the light emitting element or the light receiving element may bedisposed on the movable section. With this structure, the area where theelements are disposed can be reduced compared with the case where thelight emitting element and the light receiving element are arranged inline, allowing for reducing a space required.

Either the movable section or the fixing section is made rigid while theother section is made elastic. It is ensured, therefore, that themovable body is displaced three-dimensionally upon the application of aload to the movable body so as to effect the input as desired.

Various other modifications will be apparent to and can be readily madeby those skilled in the art without departing from the scope and spiritof this invention. Accordingly, it is not intended that the scope of theclaims appended hereto be limited to the description as set forthherein, but rather that the claims be broadly construed.

What is claimed is:
 1. An input device for a computer comprising:amovable body which displaces upon receipt of a load in a two-dimensionaldirection; a fixed light emitting element for emitting light; and alight receiving element for receiving an image of the light from thefixed light emitting element, the image of light shifting in associationwith displacement of the movable body, wherein the movable body, thefixed light emitting element, and the light receiving element areintegrally formed and wherein a unitary movable section of the movablebody encloses the fixed light emitting element and the light receivingelement such that all light from the fixed light emitting element and tothe light receiving element travel within the unitary movable section.2. An input device according to claim 1, wherein the movable bodyincludes a movable section which displaces by an operation of a user anda fixing section for fixing the movable section to the computer, and thelight receiving element is attached to the fixing section so as to facethe movable section.
 3. The input device according to claim 2, whereinthe movable section is cylindrical and encloses a detector whichincludes the fixed light emitting element, the light receiving element,and a converging lens integrally, the detector being attached to thefixing section.
 4. The input device according to claim 2, wherein eitherthe movable section or the fixing section is rigid, while the other iselastic.
 5. The input device according to claim 2, wherein the movablesection and the fixing section are molded with materials of the sametype or different types.
 6. The input device according to claim 2,wherein a surface of the movable section facing the light receivingelement is a surface-finished reflection surface.
 7. The input deviceaccording to claim 1, wherein either the light emitting element or thefixed light receiving element is disposed on the movable body, while theother is disposed facing the movable body.
 8. The input device accordingto claim 1, wherein the movable body is disposed in a space surroundedby a plurality of keys of a keyboard of the computer.
 9. The inputdevice according to claim 1, further comprising control means forchanging the shift direction, speed and moving size of a cursor on adisplay of the computer according to the displacement of the movablebody.
 10. The input device according to claim 1, wherein the movablebody includes a movable section which displaces by an operation of auser and a fixing section for supporting the movable section, the fixingsection is disposed separately from the computer, and the lightreceiving element is attached to the fixing section so as to face themovable section.
 11. The input device according to claim 10, wherein themovable body is large enough to be handled with the palm of the user,and the movable section is tilted upon receipt of a load applied by theuser in a two-dimensional direction.
 12. An input processing method foran input device for a computer, comprising:detecting a shift of an imageof light emitted from a light emitting element and shifting inassociation with a displacement of a movable body; simultaneouslydetermining from the shift of the image of light vectors in twodirections crossing each other at right angles corresponding to adirection and amount of the displacement; and synthesizing the vectorsin the two directions to obtain a synthesized vector and calculating adirection and amount of operation from the synthesized vector.
 13. Theinput processing method according to claim 12, further comprisingoperating the light emitting element to emit light intermittently,wherein in the step of detecting the shift of the image of light, theshift of the image of light is detected in synchronization with emissionof the light emitting element.
 14. The input processing method accordingto claim 12, further comprising altering a speed of indication of inputon the computer in accordance a magnitude of the synthesized vector. 15.The input processing method according to claim 12, wherein the detectingoccurs on a plurality of contiguous light detectors and the determiningincludes using signals from all of the contiguous light detectors fordetermining the shift in each of the two directions.